Among the millions of Doctor Who fans watching the farewell appearance of the time traveller's 10th incarnation on New Year's Day, possibly none will be sadder than the actor who plays him, David Tennant.
Talking on Desert Island Discs today, Tennant confesses to a lifelong obsession with the Time Lord which began after he watched an episode starring Jon Pertwee, the third doctor. Tennant was three at the time.
Tennant, who was raised in Paisley, says: "I asked my parents what he [Pertwee] was doing and when they explained he was acting. It sounded like the perfect job, which it is." He missed only one episode in nine years, and his bedroom was plastered with posters of his hero Tom Baker.
Tennant describes meeting the fourth Doctor after queuing up in a Glasgow bookshop, wearing a scarf not dissimilar to his hero's trademark number, as "an important life moment for a little me". His success as the 10th Doctor means he is constantly besieged by fans, but to Tennant this is a small price to pay for living his dream.
"I would not have given this up for anything. I did it for my eight-year-old self, which is still a huge part of who I am now. I'm proud and relieved that it didn't go wrong on my watch."
Tennant said he believed the Doctor's demise meant the first line of his own obituary had been written.