It is our choices.

As someone who has made a maddening variety of poor choices and a few excellent ones, my favorite quotation from the Harry Potter series is when Harry has worried that he is at heart a Slitherin rather than a true Griffindor, and Dumbledore says

"It is our choices, Harry, that show what we truly are, far more than our abilities."

-Albus Dumbledore

I expect Brannon, my lovely eldest, to comment with her ever ready:
"Pop's on his rant again." :-)

I have before ranted about choices here and here.