The Friends star rocketed to international acclaim when he starred as Ross Geller in the TV series but admits he never quite got to grips with fame and success.
He said: "I remember very well when celebrity first came to me. It wasnot something that made me comfortable. It was almost painful. I didn't like being treated differently than who I was.
"I just didn't respond well to it. I didn't understand why people were treating me as if I were special. I found that painful because I hadn't changed. I didn't like the idea that someone could suddenly get special treatment for doing nothing other than being on TV."
The 49-year-old actor is currently starring as Robert Kardashian in The People v. OJ Simpson and he revealed he spent two hours with Robert's ex-wife Kris Jenner to learn about the late lawyer.
He shared to Parade magazine: "I knew nothing about Robert Kardashian. I spoke to Kris Jenner about him for a couple of hours. When I learned that he was a very religious man of great faith, that held one of the keys to understanding how he could decide to stand by his friend and stick it out. Even when there might have been great uncertainty or doubt in his heart.
David Schwimmer as Robert Kardashian, John Travolta as Robert Shapiro in American Crime Story: The People v. O.J. Simpson.
"Part of it was the idea that it was not for him to judge. It was just for him to love and stand by his friend. The more I learned about Robert, I discovered that he represents the conscience or the moral compass of the whole series."
