I enjoy running, maybe something inside me is mis-wired, but I truly enjoy running outside, even in the cold. I'm competitive and enjoy pushing myself and will occasionally entering a race. It's fun to compete in a race and try to set a personal best. I've had races where my times were abnormally good. Everything was perfect that day, the weather was crisp, the course flat, competition a good match, and I was feeling good. The race went perfectly and I achieved a time that was unrepeatable, at least until events line up perfectly again. If you race enough you'll have more than one perfect day, maybe a handful, maybe a few dozen.
Anytime I ran a perfect race I knew it. I could feel that what I had just accomplished was unlikely to be repeated soon. I would enjoy my personal best, but in my mind it was always hedged with the thought that I couldn't really do it again, or maybe I didn't quite earn it.
In running like most sports the path to success is consistent practice over a period of time. You don't train for a race by running haphazard varying speeds during practice. You build up both time and distance with practice. Consistently hitting goals in practice results in predictable race times. If I could run five or six miles daily at a seven minute a mile pace I knew I could run a 5k at a 6-6:30 pace (note I said above I like to run, not that I'm fast.) My race outcomes were predictable because I had a repeatable practice process, and in practice I ran consistently.