But nowadays it's hard for me to go anywhere in San Diego in July because a lot of what I've done has some relevance in that world. Nowhere do I feel more famous than at Comic-Con because if it's not Shaun of the Dead then it's Star Trek, and if it's not Trek then it's Star Wars. It's incredibly hard to leave my hotel room because the moment one person sees you and asks for a photo you're suddenly getting mobbed.

One year I went out wearing a Joker mask from The Dark Knight, but it was just too hot, and I was really sweating. Every time I pulled it up just to breathe, I'd get mobbed. When I came with the film Paul in 2010, Sigourney Weaver was with us, and she went out on the floor as Batman — she had the full cowl on. She's 6 foot and incredibly imposing, so she probably drew as much attention in disguise as she would have without it, but she was able to wander around and have a look about.

Then, in 2013, I was in New Zealand on the press tour a few days before Comic-Con, and somebody — a prop builder — had given me a homemade Shaun of the Dead Boba Fett helmet. It had a little cricket bat in place of the antenna. So I had this brilliant mask, and I thought I'd hide in the light and go as a Shaun of the Dead Boba Fett. I got this T-shirt with the red tie and the "My Name Is Shaun" badge because I thought it would be a bit cheeky. The helmet smelled a bit funny, like resin glue, but I had a nice run of Comic-Con in it. But then someone came up to me and said, "Can I have your autograph?" I was like, "How did you know?" Then I realized I had my accreditation on, and it said "Simon Pegg" in big letters. I turned it around and walked around for about 40 minutes with impunity.

So over the years I've sort of honed my Comic-Con disguise technique. I've learned various lessons about keeping cool: Don't go dressed as a Stormtrooper because it's going to get very warm; wear something light and cool. Move fast, and don't wear your name badge. I feel I've lost a certain amount of freedom to have that privilege to walk around the floor unfettered, but it's fun to walk around the floor and look at people wearing masks and wonder if there's someone you might know under there.

This story first appeared in the Aug. 5 issue of The Hollywood Reporter magazine. To receive the magazine, click here to subscribe.