Why dislike or downplay something about yourself? It's so much more fun and makes for so much more of a happier, healthier person if you accept and love all that makes you what you are. I know you aren't supposed to say this, but... I love the way I look. Do I have Angelina Jolie lips or hair like silk? No, and I don't care. When I look in the mirror sometimes I can see my dad. I don't have a beauty queen smile with a giant toothy grin, I have a smirk - just like he did. I have big brown eyes that may or may not look like a terrified deer, but my daddy's eyes were the same color brown. I used to be jealous of blue-eyed people, why I don't know now. I love my eyes. Nobody looks exactly like I do, and if there is a doppleganger out there, I'd think they were the second coolest looking chick ever.
Also, I am smart. Smart enough to realize that I need to learn a whole crap ton more than I already know before I should publicly make that statement, but fortunately enough, I am smart enough to learn most of it. For this I am grateful and I strive to learn as much as I possibly can. The only thing in life that truly bothers me is that I will never have enough time to learn how to do everything. I want to be a chef, a lawyer, a doctor, a photographer, etc, and I'll never live long enough to accomplish and learn all these things, but I will continue to try. I really hate it when people say, "I'm not smart enough to do that." More than likely what they mean is, "I really don't have a desire strong enough to do that."
I find having a self-effacing attitude to be especially boring. If you think there is something special about yourself, embrace it. If you don't think there's anything special about you, you're wrong (remember from above when I said I was smart? I know these things). Everyone is different and unique. Love your weird, unusual, crazy, etc. Conventional beauty is often tiresome and no truly smart person wasn't a little insane. Don't be humble, be you.
***Note: This post is not promoting douchebaggery. Being pompous, pretentious, narcissistic or an unrepentant braggart is not cool. Find a happy medium. Love yourself, but don't expect everyone else to revel in your awesomeness.