Patrick Dempsey turns 45 today.

We'd list at least that many reasons why the Grey's Anatomy star deserves birthday greetings on this 13th day of January, but come on, you already know them.

The actor, racing enthusiast, philanthropist and father of three remains remarkably grounded despite his fame, which has always been one of his best qualities.

Some of you will probably put "looks" high on the list as well, and he is pretty good as Derek Shepherd. Point ceded. Anyway, have a happy birthday Patrick!

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.