I had to think about this for a moment. Not that I had all that many moments, but one in particular stands out as it shaped my later years. I was a good high school football player, undersized for the O line at 5'7", but I was also a good high school wrestler so I understood leverage and position more than most.
The story: in 8th grade we were a good team in football with one loss or something and tied with around 2 minutes left in the game. We were on defense and I was playing defensive tackle. Not strong enough to bull rush the guy, I typically had to use quickness to fake line way and then go another. At this point I was tired and my move didn't pan out and I was late getting into the backfield but just in time to see the ball squirt out of the pile. I reached down, scooped it up and it was off to the races. With the goal line about 70 yards away I ran as fast as my short legs would carry me. Around the 20 yard line I looked to my right and left, seeing teammates I eased up just a bit and was suddenly tackled from behind at the 4 yard line. We had about a minute and a half and 4 plays. We didn't get it in. On the bus back, everyone, coaches, players and even the friggin cheerleaders said, "if you were just a little faster." That summer I promised myself that I would become much, much faster. I ran that summer. Living in the country, I had railroad tracks to run on so I chose the challenge and worked on my foot speed by making myself hit nearly every railroad tie while I ran as fast as possible.
The next time I took the football field, I was the fastest lineman, not one of the slowest. We went on to go undefeated my senior year with 8 shutouts but didn't make the playoffs due to computer points. I played both ways and ran a respectable 12.0 seconds in the 100M. Even though I had 10 varsity letters in football, wrestling and track, I will never forget those words. Yes, I listened to the Rocky soundtrack on a cassette player while running.