As Matt Smith's time-traveling days on "Doctor Who" near an end, he admits that there are moments when he wonders if he'll deeply regret his decision to leave the beloved sci-fi drama.
"Just because I've done 'Doctor Who' doesn't give me a divine right to walk into any other jobs," he told journalists gathered here for television's annual summer press tour. "I have pondered it on several occasions and sometimes think, 'I've made a huge mistake. What am I doing?' Don't leave.'"
Smith, the 11th actor to play the eccentric, two-hearted alien, is preparing to shoot his farewell episode -- the show's Christmas special, which will arrive on the heels of the much anticipated 50th anniversary special.
He called the decision to leave after four years "a hard choice," but pointed out, "I've done it for four years, and we shoot nine, 10 months a year. The show has come to a natural tipping point. It's at the top of a cycle and it's a good time for me and the show."
Smith added, "I feel very proud to be a part of such a wonderful legacy. The thing about Doctor Who is he always looks forward. The show will get bigger and better and carry on without me."
He called his time with the show "a transformative experience" that has dominated his life.
As far as future jobs are concerned, Smith already has one lined up: He'll star in "How to Catch a Monster," a fantasy film produced and directed by Ryan Goslin.
Meanwhile, the search for Smith's successor is ongoing, according to "Doctor Who" producer Marcus Wilson.
"You want the best actor for the role," he said. " ... You just have to cast the net wide and hope you find somebody brilliant."