Doctor Who star Matt Smith has said nothing can prepare Peter Capaldi for the job of taking on the role of the Time Lord.
Matt bows out at Christmas and will be replaced by The Thick Of It star next year.
He said: "I don't think anything can prepare you for the experience of what being the Doctor in Doctor Who is but I think he's as ready as he can be.
"I've just said 'Have a good time, mate'. He'll be great - Peter will hit the ground running and keep flying."
Matt added that he was looking forward to bowing out and said show boss Steven Moffat had given him a great exit.
He said: "I'm really excited about Christmas. I think Steven has written a real belter for me to go out on and I had a great time filming it.
"It was quite sad at the end, obviously, when I had to leave, but I think we've got a really moving story, a really great sense of adventure in it which I'm pleased about because it's obviously the last episode but it still feels like a classic adventure episode with great monsters and a few twists."
Steven said he was not worried about the 50th anniversary overshadowing Peter's arrival.
Speaking at the Official 50th Celebration at the ExCeL Centre in east London, he said: "I'm rather excited at all this hoopla - after all this enormous party, we just throw another one.
"You wait, 30 seconds after I've stopped saying the 50th special is the biggest Doctor Who story ever, I'll be saying that the Christmas one is and then I'll be saying Capaldi's first one is - that's the nature of the show."
Thousands of Doctor Who fans descended on east London for the three-day celebration of the show.
Dozens of doctors - in fancy dress from every era - rubbed shoulders with tinfoil cybermen, daleks and endless aliens, with around 24,000 people expected in total.
The event includes interviews with dozens of the show's cast and crew through the years and a chance to go behind the scenes and see how it is made.
Matt said the fans made him realise how much he will miss the show when he leaves.
He said: "I'm going to miss it terribly. I really will miss it, God it's a really unique rare thing and it just compounds how much I'll miss it when you come to stuff like this."