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.
best to put level in your expectation and not over expecting , greed takes place once you desire for so much when you already have best , imagine already gain double but looking for more? then that is already greed and need to be changed .
So all in all, do not make all the mistakes confused with each other, because emotions in trading world is very dangerous
emotion must not take place , when you are trading because this will affect your decision making and most of the times? to wrong side.