David Tennant has told how he found his rise to fame "terrifying" after landing the lead in Doctor Who.
The actor, 41, quit the BBC1 sci-fi show in 2010 after four years occupying the Tardis.
He told the Radio Times that he had not been typecast since leaving, and that the role had opened up more doors than it had closed.
But Tennant said of getting used to being recognised: "No one can teach you what it's like to be observed in public.
"I remember, before I was that person, watching well-known people walk into a room - you imbue them with inner confidence and a slightly royal presence.
"Yet when it's you, it's terrifying. People lean over in restaurants and say, 'Don't look now, but that's him off the telly'. Very peculiar.
"I'm not moaning - there's nothing worse than that, because there are huge advantages - but you feel vulnerable," he said.
"The world's perception of you has changed while you remain the same."
Tennant, who married actress Georgia Moffett, 27, on New Year's Eve after they met on the set of Doctor Who, said actors should not have to be role models.
"There's a sense everyone in the public eye has to have moral purity," he told the magazine.
"Personally I might agree that's a good thing but I don't see why, because you're in a TV programme, you have to be perfect.
"Actors often get a bad press, but 87.5% are down-to-earth and reasonable. Difficult ones are becoming rare because the world doesn't allow it. They're usually not the big stars but those who believe they should be."