What are you good at?

Someone asked me that the other day. What are you good at?
It caught me off guard. I thought about it for long enough that the silence became awkward.
It's such a simple question. Such a hard question to answer.

I can tell you what I'm not good at. I'm not good at anything that requires coordination. Sports, for example, I try them all out but I'm not good at any of them and when dancing there's no grace. Singing is pitchy and terrible. Being brave, definitely not something I could put on the ol' resume. I am a terrible student and am not good at anything that requires patience. I am not good at expressing any feelings in a remotely sane and sensible way, instead preferring to bottle it all up until it comes out all at once in a raging flood. The list goes on.

So why, if that list is easy to come up with and could be easily expanded for pages is it so hard to answer, what am I good at? Is it that we're trained not to think of ourselves in a positive way? Is it that we never examine ourselves looking for the things that make us great? Or is it that we're just so busy focusing on the things we're not good at that we have simply long forgotten what those other things are?