Greed isn't a black or white type of thing, you are not going to see how that works at all, and you wouldn't know if you are being greedy or not. Just because we can use the word easily, doesn't mean that we are going to be able to realize it when it is happening. Of course if you buy something cheap, wait until it goes up, do not sell at the top, and then the price goes down, you will be able to say you were being too greedy afterwards, but you are only capable of saying this afterwards.
Greed is not new and there are actually explanations on how it works and on how it can be prevented. Concerned people can learn from it and they can even apply it but there are still times that they can not take it anymore. The only best solution for this problem is stop doing that activity that makes you greedy and affect your life in a negative way.
you will be able to say you were being too greedy afterwards, but you are only capable of saying this afterwards.
I think you mean to say is that we will only realize or say it in our head first? But if we have no person to talk about or we are shy, we will still be like this afterwards because we will only look crazy if we will say things loudly when there are no other people around.
In trading or investing, there is what we called as analysis. It basically works like a guide to somehow know if the price of the crypto can still increase or not. For those who are totally clueless, why will they bother wait? For what? They should be the ones who are going to be greedy here. Selling earlier but still ends up in profit is still obviously better than waiting for more but ends up losing the opportunity.
This shows that being greedy is sometimes a good thing too, or it has two sides/scenarios. If only BTC is the coin that we are talking here, then there are exceptions. I mean we can wait much longer for it, as it is a proof that history really can repeat itself. I'm only referring to its pumped price here because it can dump as well.