Robert Pattinson got his start in Harry Potter and the Twilight star says he's delighted he didn't stay at Hogwarts.

Pattinson played Cedric Diggory in "Harry Potter and the Order of the Phoenix" with Daniel Radcliffe and Emma Watson, and he says that was quite enough for him.

He says there's no way he could have kept the pace on the Harry Potter series.

"The 'Harry Potter' I worked on was an 11-month shoot,'" said Pattinson.

"I couldn't be doing that. I don't know how those guys stayed sane — they've been doing it for 10 years. I would go completely crazy."

Pattinson says he has no choice but to complete the Twlight franchise.

"I guess I have no choice right now — because I'm contracted to do them. But they're all going to be done quite quick. I'll have done three of the four by October of this year, then I'll only have one more to do."

Meanwhile, Pattinson's co-stars said his succes was no surprise.

"He was always very intelligent, nice, talented, good-looking, had everything there," said Emma Watson.

"I'm not surprised he's been successful. I'm surprised that it's got this insane. I think he's a great actor."

Radcliffe said Pattinson's rocket ride to fame had given him a new perspective on Harry.

"I have no concept of what 'Potter' looks like to the rest of the world because I'm so involved in it. So to watch 'Twilight' kind of explode globally had been fascinating."