In the world of scripted television, reaching 200 episodes is a milestone achieved by only an elite breed of series – enduring classics like “The Simpsons,” “Gunsmoke,” “CSI,” “MASH” and “Cheers.” “The Big Bang Theory” now joins that rarefied club, a distinction that would most certainly go to the head of its ambitious, obsessively numbers-minded physicist Sheldon Cooper.

But for the actor who plays him, Jim Parsons, the landmark is a moment for reflection on an ever-ascending creative ride that has led him to achieve top ratings in the nine-season run as one of the most singularly unique sitcom characters in recent memory, to earn one of the most enviable salaries on network TV and to collect a mantle full of trophies for his performance, including four Primetime Emmy Awards. Parsons joined Variety for a look back on how the bang kept getting bigger and bigger.

Now that the 200th episode has been done, I know you were glad that it wasn’t a “very special episode,” but it is a major milestone. Having hit it, do you feel like you’ve accomplished something pretty special in your career?

I do, I do. I don’t feel overly personally responsible for it, but I do feel pretty flabbergasted to be a part of something… Now as we talk, we’re working on our 201st episode. That astounds me.

I think for most people, especially actors, the goal is to work. And you can know where you think you might be best suited in the industry, but the industry’s always pretty quick to confirm or deny that for you, you know. So you might as well just do your thing and see where you land, in a lot of ways. And that’s kind of how I feel about this, and I always have, and how I feel about the 200th episode. It’s like, “How the hell did this happen?” In the best way, obviously.

I don’t want to say I feel mystified by it, because it’s not like I feel like, “Well, this is not very good. How?” No. I feel very proud of the work we do. I love coming here, and one of the more astonishing things I think I already said to you is how enjoyable it still is, to do this job, at a very visceral level as an actor, this far in – and again, all credit to the writers for that. Just the whole staying power of the whole engine – there’s just no way to predict for it.

Turn back the clock and tell me what was happening with you and your career when the show first came to you. Were you feeling good about the path you were on, were you ready to give it up? What was happening when “Big Bang” came your way?

Looking back, now that I have something to compare life to, I think I was probably feeling really good, except I didn’t know exactly how I should or shouldn’t be feeling at that point. But I was very fortunate to start working as soon as I got there in New York. I’d gotten an Off Broadway play – which didn’t pay diddly, mind you, but that kind of wasn’t the point at first. It was like, “Just get involved in some way.” And then it kind of just went from there.

I did a couple of commercials and a couple of guest spots and a couple of little movies – not “little” movies: smaller movies, not big studio films – and I had gotten a couple of pilots that just hadn’t been picked up. So think I felt like it seemed like I was headed in the right direction, although again I didn’t know where that would actually land.

But I did feel that when I read “Big Bang” it was definitely special to me. I would definitely not presume to say I thought it was going to be a hit show or be picked up, but I know that I was being presented with a character that was, in its own weird way, a really good fit, that I thought I could do.

You saw the potential in the role, for what you could do with it. When did you get that sense that something special was happening between you and Sheldon? Like, “Oh, we’ve got something here?”

I would say that some of it was gradual and some of it was sudden. The sudden part was the taping of the pilot. It just went very well, as far as audience reaction and the amount of just genuine laughter. And nobody knew anything. Nobody had met these characters before, so it was all… It was either going to make ’em laugh or it wasn’t. You were being introduced to all of this as it went. And that tape night went very, very well. I felt that they had assembled a real tight machine here.

The next phase was more gradual, once we had been picked up. We were maybe four or five episodes into the season before anything had aired. And reviews started coming out and some were positive and a lot weren’t, and I just thought… “I’m there.” I could never speak to what an audience is going to take to en masse to keep it on the air, but this is not subpar work being done, in any capacity. The writing, the acting, the directing – everything’s going very well. So this is not a bad show we’re doing. It’s a really solid effort here.

And what was really nice about that was we had a couple of years under our belt by the time it was like “Oh my God, we’re a top-five show.” And then they’ve got us behind “Two and a Half Men” and it’s getting all these new viewers and there’s attention. And there was this foundation we had built. We were still coming to work and doing the same work we had been doing all the time.

This is the only TV show I’ve ever been on as far as from the beginning, so I don’t know what it’s like to be one of these TV shows that’s hot right out of the gate. I imagine it’s very exciting, and I imagine it can be very gratifying, but also my human instinct thinks it must be very frightening. We were never playing to keep the lead, as they might say in sports, do you know what I mean? And so we kind of kept doing our thing, and by the time we were doing well, you just keep doing what you were doing. We weren’t like “Oh God, what were we doing that was working so well?” It was, certainly for me, the best way that this could’ve gone.

What has been your favorite part of paying the character over the course of all these seasons? The element that you’ve enjoyed throughout the run that always keeps you excited to go to work?

In a very specific way, one of my very favorite things about this character is his sort of lack of sentimentality. I don’t mean to sound unromantic or unsympathetic, but I cannot stand sentimentality, and I feel very lucky to be playing a character that, nine times out of 10, when something sentimental is happening in a script, I get to be the one to burst that bubble. And that gives me such great pleasure, I cannot tell you.

And I guess in a general way it relates to the thing that I loved about him from the moment I read the pilot, and for nine years now, which is just enough level of cluelessness to get away with saying some of the most outlandish and inappropriate things. For my money, one of my favorite types of humor is people not understanding the situation and plunging forward in it. And as an actor it is just really fun to get to do that, to get to say inappropriate things and, frankly, to have a character who comes by it honestly, who’s not trying to be mean.

The show is firing on all cylinders creatively as much as it ever has been, and yet you guys are certainly closer to the end than to the beginning. Tell me about that – do you think about the end? I know some of your co-stars just refuse to entertain the thought. How do you feel about it?

Yeah, I think about the end. I think that I can’t work under the umbrella of “Things are winding up around here,” because I think it’ll be a while before I understand when the actual end of this glorious tunnel is. But as far as looking at life realistically and my own age and places in life and things like that, yeah, my mind flips there sometimes.

I think I would be afraid to go down that road if I felt anxious about it – like, “Oh God, let’s just wrap this up. I’m ready to – I don’t even know what – move on or whatever.” But I don’t feel that way about it. And yet there is another half of me that I’m just young enough to feel really excited about whatever happens after.

All that being said, I am painfully aware that if things keep going the way they’re going – and by that I mean as a cast we have a good time together, which I think we’ll manage, but more importantly the stories are still so enjoyable to be a part of and the writers are still so enthusiastic about character and plot points – if that just continues on through the end, I predict I will feel really good about wherever we wrap it up, as in, “We left it all out there, we did what we were supposed to do,” and whatever.

I don’t think that when the time comes I’ll feel like, “Oh, I miss doing the actual show.” I really feel like the way this is going, all I’ll feel like is, “We did it! We did that show.” But I do think I’ll desperately miss something that’s easy to take for granted, which is having this five-day-a-week job for nine months a year. It is such a rarity as an actor, and I don’t mean to highlight the banal or what may sound banal to most people, but I don’t think people who aren’t actors or work in this industry would understand in some ways the strangest part about this run, is how long we’ve reported to this job every day for five days a week, nine months out of the year. It’s almost unheard of.

You literally have to go through every other series that ever hit this many episodes and go “Well, there’s your comparison” – and other than that, there is none.  am a creature of habit, and I will have a physical reaction to that, I promise you! I pray it’s not a breakdown. How could you not?