I can agree to it because I experienced it before.
I have 2 reasons before:
1. It's either I can't sleep because I am excited about how to spend my winnings

2. Or I can't sleep because my winnings are not enough and I am still willing to play more, bet more, and expect to grow those winnings.
Yes, it will be more about imagining what you're going to do next. I can feel it, and I believe that is the thing that happens to most of us. We don't know why, but our minds kept thinking about it until it was done.
That is to agree, saying that winning is not good. It can also be a source of mental stress. While many gamblers win, the more they become addicted to gambling. Yes, that possibly happens because of greed, and such winning experiences drive them to think there is more.