Mindy Kaling, after being asked, a gazillion times, where she gets her confidence (from Why Not Me?):

"People talk about confidence without ever bringing up hard work. That's a mistake. I know I sound like some dour older spinster chambermaid on Downton Abbey who has never felt a man's touch and whose heart has turned to stone, but I don't understand how you could have self-confidence if you don't do the work. I work a lot. Like, a lot a lot.

....The reason I'm bringing this up is not to defend my status as someone who always works. (I swear I'm not that Tiger Mom lady! I don't think you need to play piano for eleven hours with no meals! Or only watch historical movies, then write reports on them for me to read and grade!) It's just that, the truth is, I have never, ever met a highly confident person who is not what a movie would call a 'workaholic.' We can't have it both ways, and children should know that. Because confidence is like respect; you have to earn it."