It's true that performance while tired might not be as appreciated and practiced as much as it should be. But don't get overly enthusiastic in training high-skill movements while exhausted. Remember that more sports are won and lost by the starters in the first half than by the scrubs in the second half. On average, performance while fresh is still much more important than performance in a fatigued state. Injury rates also go up dramatically when tired, especially with high skill movements. Proceed with caution.
Here's something useful I learned about myself as a kid. I went to the family doctor for the usual case of teenage angst, aka raging acne. He mentioned that jams and jellies might make acne worse. True or not, I believed him. Now, I'd been eating jam and jelly since I was old enough to chew toast but from that day forward I became someone who didn't eat jam. Just like my brother who didn't eat mushrooms, I didn't eat jam. I just didn't. No big deal, it's just one food out of thousands. To this day I don't know if jam made my acne worse but I still don't eat jam. I learned it's no big deal to drop a particular food out of my diet, even if I enjoy it. There are other delicious foods.
Later on in life I became someone who didn't drink sodas, diet or otherwise. I decided that soda is a ripoff and almost certainly not healthy. Fat people drank sodas. Sodas were mostly water and chemicals. McDonald's profits come from sodas. It was no big deal to stop ordering sodas at restaurants; at the very least water is always an alternative. After a while, people learned to stop offering me soda. No explanation was needed, they learned I just never said yes. I became someone who didn't drink soda, like some people don't eat fish. I learned that other people can usually accept our dietary peccadilloes especially when no explanation is offered.
At work people learned that I don't eat pizza. I'd offer no explanation -- I just don't eat pizza. They learned, they accepted, I ate something else. No big deal. Most people have a list of food they won't eat. Most of the time the "why" doesn't even matter, even if in our opinion they are being irrational or unhealthy about it. They don't eat this. I don't eat that. We eat other things. Life goes on.