Rather than a trait, is courage an act? A verb? If so, I'd wager you don't know when you're doing it (Hey, last week I guess I couraged!), but you sure know when you're not (Shoot, today I'm not couraging).
But some people have a better handle on the courage thing than others. I know, I have brave friends and hide behind them on a regular basis. They sport the coveted hard psychological candy shell but have a sweet and soft center. We are not of the same species.
If I could change anything about myself, it wouldn’t be higher IQ. Prettier smile. Better backhand. It would be a here-I-am-and-what’s-it-to-you attitude towards life. It would be going toe-to-toe with anyone who challenged me. Instead, my preferred method of response is to disappear. Oh, it's not a physical danger that worries me -- worse than that -- I just don't want my feelings hurt.
In fact, physically, I'm close to fearless, and will walk down any dark alley with nothing on my mind but what's for breakfast. But if you call me out on a blog that seemed rude, I'll be up all night posting dog pictures. (Because my old boxer looks just like Grandma Moses and will eventually melt your heart.)
Courage is a strange and elusive animal. I can spot it on a mountain top or ski slope. It comes to me when called, but only when I'm high above the clouds and the sun is shining.