I agree with you that it is not fun to happen when the investment we have actually decreased not ccording to what we expected, but in crypto we actually have to instill from an early , that it is very possible and is not a strange thing.
In theory, it is true that buying when prices fall and selling when we consider it worth selling, but in practice it is not easy.
it could be wrong to anticipate because the most basic things are greed and panic.
I believe you could get better and better with time when you are hodling. For example, if you invest all of your savings (still money you can hold) into bitcoin and the moment you invested it started to go down, you bought at 40k and it never returned? That scares people, and scares a lot as well, that is really not something you would be fine with and you may end up selling as well cutting the loss and getting out, I would understand those people, they are not used to the market and they got scared, I would advise them not to but I also understand it.
However another thing about this is the fact that we live in a situation where people who bought at 20k, saw that their price went down so much that it became almost nothing but then became 2x profit later on when they didn't sell, so people who have been here for a while know that holding for long time definitely helps.