Matt Smith has revealed his mum wanted him to continue as Doctor Who, but he knew it was time to quit the show.
The actor has played the current incarnation of the Doctor for four years and is due to hand over to new Time Lord Peter Capaldi at Christmas.
He told Metro: "It was always going to be a difficult show to leave. Filming endings is sad and I've had such a ball. And my mum wanted me to stay. But I think for me and my career, it's the right time. When a Doctor leaves, the show gets a new lick of paint and a new energy."
On his favourite thing about the role, Matt said: "The wonderful virtue about playing him is you get to be the cleverest person in the room. You get to be the TV Hamlet. Deep philosophical sophistries are my thing."
Matt, 31, said there had been a tough side to playing one of the most famous roles on TV.
He admitted: "There's a big invasion in your life. Sometimes the pressures can be quite terrifying. It's something that you need to adapt to. I think it comes with the territory, it's part and parcel of being the Doctor. It impacts not only my life, it's my parents' lives and my friends' lives too.
"Mum goes to the shops and it's, 'She's Doctor Who's mum,' and people start asking for stuff, for charity and stuff, stuff to sign. It's all for the good - and you know, you can never say no to your mum. And the fan stuff is so positive. You'd have to be a bit of an a*** to be grumpy with nine-year-olds who love the show."
Matt also revealed he was once approached by a fan while he was having a wee.
He told BBC Breakfast that he was asked to chat on the phone while standing at a urinal, but managed to finish what he was doing.
The 31-year-old said : "I was caught actually going to the toilet once, for a wee, and someone had his wife on the phone they were like can you speak to my wife.
"I was literally having a wee. and I was like aahhh, just give me a moment."