What to do when your best isn't good enough

What do you when you try your best, whether it be in a race or some other athletic activity, or even in life in general, and it just isn't good enough? Sometimes you may find you thought you were giving 100%, when in reality it may have only been 95%. Other times you may have truly given 100%. During the activity, can you really tell the difference, or does it depend on the situation?

According to my VO2 max testing (two different testing protocols), I have a potential to run a sub-three hour marathon (one test actually had me closer to a 2:20). Interesting. How cool would that be? I guess I could get there if I didn't require any income and could simply train full-time. Not to mention the will to get there. I think I'll be satisfied if I can get to 3:20. Of course that is likely based on statistical projections, but I can't help but wonder what might have been, had I understood it and not only had the drive to get there, but a coach and an understanding of how to train for it.

Upon reflection, if you think you had more to give, you can use the information to dig deeper the next time. But what if you had been giving 100%, but the results are unsatisfactory? You can change the way you train, change behaviors, and work smarter/harder to improve. But what do you do if that still doesn't cut it? Keep working to find a way around/over the wall? Accept it? Choose a different wall? Of course it depends on priorities, time, and will, but what if your best still doesn't cut it?