Yeah, and it's really hard to learn it, others have experience but it's not a the only thing that will let you know when to get out. I guess one strategy that I use is to have a exit plan, at least if I have achieved my it, I will simply get out and not look back.

No regrets whatsoever if the price continue to increase after I sold off. It's not the nature of crypto, very volatile and unpredictable. And you mentioned greed, yes, that's another emotions that we traders need to get ahold of. We should unless not to get carry but this emotions because in most cases it will spell between a successful trade and profits and losing more money in the end.