Having greed is good, its the stupid mistakes that make you lose money. Greed is wanting more money, holding more than you should is not "greed", its a mistake, if you know what you are doing then you would sell at the top and buy at the bottom and make more money aka be greedy.
So all in all, do not make all the mistakes confused with each other, because emotions in trading world is very dangerous and mistaking which emotion is which could be even worse and that's an important thing.
honestly it's hard differentiating greedines and just mistakes, I mean if someone is holding for longer just because they want more profits isn't that essentially a greed, because they just want more and more despite already having good profit if they could just realize their floating profits, i'd consider decision that was made before hand basically part of strategy as a mistake if it turns out wrong but if it's holding for longer just for more profit and as it turns out, the coin is losing value instead, I think it's just greed, nothing more.
it is more differentiate if what kind of coins are we holding to determine our greediness , if you are keeping shitcoin and even if it already increase 100 and yet you are waiting ? then that would be greedy ,
But if you are keeping like Bitcoin or top coins? then waiting even for how many years cannot be consider as greed because there are always potential of climbing.