4 days:"If you want to be good at something, you gotta be obsessed with it" -My psych prof

It all comes full circle when as Doctor 10, he gets to play opposite his favorite Doctor, Peter Davidson in a Children in Need short.
"You were always my favorite," wasn't just the Doctor being nostalgic, it was Tennant fanboying a bit with Davidson.

Who later also become his father in law.

I READ 'DAVID TENNANT' AS 'DONALD TRUMP' AND I WAS SO DAMN CONFUSED FOR A SOLID FIVE MINUTES