I am always wondering why people talk good things when they are...

I am always wondering why people talk good things when they are a holder and completely different person when they sold it. One reason- people FOMO and sell so they can get in lower? Second- they are just kind to warn others. But it depends on how they write and respond. Only those people know better than anyone else. This is because not I have seen here but seen in almost every stock. They dont move on after they sold. They will keep backslapping until they get their results? I believe everyone here is all adults who can judge themselves what/why they buy and sell.