Continuing my last post: I think I must acknowledge that a significant reason I never try my hardest is because I enjoy not knowing my limitations. If you don't know what your limitations are, you don't have to acknowledge that you have any. Thus I am able to go through life with the firmly held belief that if I had really wanted to I could have done X or Y or Z, where X, Y and Z are whatever truly amazing feat catches my fancy that day.
Of course, there are areas where even I must acknowledge that I could never have excelled. For example, I could not make a living as a Mary Kay saleswoman. I also could not be a professional golfer, tennis player, figure skater, or really any other type of athlete. I could not have a job that required me to drive one of those big rig trucks. Or really any job involving driving. I do not think I am cut out for teaching children. High school I probably could do. But not alternative high school students who don't know how to read, like in Push (aka the Precious book, which incidentally I don't see how it could have been made into a movie without losing much of what made it great). Anything that requires patiently dealing with people who are slow to grasp things or have limited understanding I could not do. Actually anything that requires patience period. I tried learning computer programming once and had to rule that out too. I had perfect scores on everything going into the final, and then I hit a brick wall. I could not have completed that final -- I think you had to set up a sort of web site arcade that kept track of high scores on a game or something -- to save my life, in the improbable event that a web arcade would save my life. I could not be a chef. Or a waitress. Or anything else that requires being on your feet all day. I once had a job as a security guard at a museum and had to periodically find an empty gallery to squat down and rest in. I also once had a job as a receptionist and was fired because I couldn't get the hang of the phone system and kept hanging up on customers. But I wouldn't rule out receptionist entirely. I think I might be able to handle answering phones now.
On the other hand, I think younger versions of myself might be very surprised that I became a lawyer, and might have thought I wouldn't be any good at it. When in fact I am very good indeed. But not as good as I could be.