Doctor What?

I was on YouTube a while back, and I was watching a Doctor Who video.  After the video was finished, I looked down at the top comments, and someone had said something about their favorite Doctor, and “their Doctor.”  I’ve never quite understood the concept of “my Doctor” and my favorite Doctor:  what’s the difference?  Is your Doctor supposed to be the one you started watching first, or the one who made the most impact on you?  It’s just overall confusing the heck out of me.  So I’ll just put this out there:  10&11.  My favorites.  The first episode of Doctor Who I saw was “Flesh and Stone” I believe.  So the first Doctor I have watched on television was Matt Smith.  At first, I used to refer to Eleven as “my Doctor”, since he was the first one I saw.  But then came David Tennant.  I had heard so much praise for the tenth Doctor, I thought, “Well, I better watch his episodes, since everyone is so fond of him.” I understand why now.  I absolutely ADORE Tennant.  I’m starting to watch season two, and every single episode just makes me love him more.  So overall, the Tenth & Eleventh Doctors are my favorites.  But this is just really bugging me, and I might sound stupid for asking this, but what the heck is the difference between “my Doctor” and “my favorite Doctor”?