Green names get in here

I've never written anything good but I have an idea for a story about a less than good journeyman mma fighter making a comeback. I have personal experience (of not being good) but I'd like some real life stories from other guys who have, despite physical or emotional issues stepped into the cage and competed. I'd like to know your story, what exactly kept you from being a success, but why you did it anyway. 

I never hoped to be a success story personally, but felt a need to challenge myself. I'd like to hear the tales of others. Please post in this thread or pm me your story. I can't promise it will turn into anything, but maybe it will be cathartic for us.