Roller derby gave me a gift. That gift was relief from the constant stream of self-critical chatter in my own head. Well, the real truth of the matter is I gave that gift to myself, but derby was the medium in which I began to understand that my habit of negative self-talk was not enriching my life, nor the lives of those around me. Telling myself I suck didn’t help me learn a hockey stop, it didn’t teach me a strategy, it didn’t help me become a good teammate. Giving myself mental space to mess up and not beating myself up over little failures did, though. I gave myself permission to have fun without being perfect. A good life lesson, it turns out. It…