Why Starring on Dawson's Creek Gave James Van Der Beek the 'Lamest Form of PTSD Ever' (Exclusive)

When James Van Der Beek was cast in the hit teen drama Dawson's Creek at 20 years old, it was a career-making turn for the Connecticut native, who, until then, had his heart set on being more of a low-key theater actor.

The sudden fame, he says, was totally jarring.

"When it first started happening, the people who were coming up to me were teenage girls who were screaming," he says with a laugh, noting that hordes of giggling girls still put him on edge.

"So I have what I call the lamest form of PTSD ever, which is when I hear teenage girls go, 'Oooh!' When I hear that titter, I go into a still space... [then] I'm like, 'Dude, get over yourself. They're not doing that about you. You're a 47-year-old grown-ass man. They're not about to come chase after you!'"

Van Der Beek, who recently opened up in PEOPLE's cover story about dealing with colorectal cancer, has an appreciation for the fans of the show now, but at the time he says being wildly famous was tough to handle.

"Getting recognized is something that took me a long time... I had a big learning curve on it," he says.

"It was a different interaction back then," he adds of the screaming girls. "Now, it's a lot more grown-up, and back then, I was so tortured about it because I loved being an observer and a fly on the wall and having random conversations with people."

He continues, "I remember being so broken up about the fact that those random conversations or random acts of kindness were now taken away because there was this thing called 'celebrity' in between me and somebody else, and it became the center of attention."

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Now, he says, he loves it when he gets to stop and talk with people who recognize him when he's out and about.

"I have a completely different view on it, which is, now, if somebody comes up to me, I get to have a conversation with somebody that I never would've had otherwise because this thing called celebrity brings us together in that little moment," he says.

He admits he does come across the occasionally giggly girl (or woman!) when he's out in public, especially now that shows like Dawson's Creek, How I Met Your Mother, Don't Trust the B---- in Apt. 23 and his hit film Varsity Blues are being discovered by a younger generation.

"We were in a mall with the kids about a year ago, and I heard that titter, and I was like, 'James, it's not you.' But then we walked, and I still heard it behind us, and I was like, 'Dude, it's not you. They're 13 years old.' And then we stopped somewhere, and they came up to us, and sure enough, they had just been watching Dawson's Creek or How I Met Your Mother."

He laughs about how antiquated Dawson's, which ran from 1998-2003, must seem to people these days.

"When a teenager comes up and says they just finished Dawson's Creek, I'm like, technology-wise, is that the equivalent of me watching Little House on the Prairie when I was a kid? Because we didn't have cell phones or internet. They say, 'Yeah, it's like a time capsule.'"