People are weird when they earn money

I have read toons of posts from many people than claimed are holding bitcoin since 16k-20k and getting nervous and selling bitcoin st 45k... I just don't get it. You holded through the longest bitcoin bear, the harshes constant criticism, months later when bitcoin is showing clear signs of the beggining of the bull markets, 150% YTD, ETF incoming and huge institutional interest, records in every important metric on adoption, hashrate, regulations etc. Thats when people get nervous and sell Bitcoin... I don't get it, is there any psycologist here that can explain that? Do some people get nervous when they see their bitcoin is going up or what? Or it's just that there are a lot of lazy investors that doesnt research and read in Twitter than the ETF will be the 'sell the news' event and they belive it and sold?.

I don't have any point really, but i just feel bad for this kind of people, selling satoshis right now is a huge mistake.