The other things you mentioned also happen in the stock market. When prices are up, people think it's too expensive to buy; when the market crashes, they get scared and don't want to buy something that's obviously on sale. Even worse, if they sell at a loss when the stock they own starts to plummet. The markets are a weird taste of human psychology.
Yup, it's a universal thing. Markets are all about psychology, which is why gauging sentiment can be really useful as a trader. I always watch things like the Speculation board, Crypto Twitter, the Tradingview chat, and Bitfinex/Bitmex long vs. short data to gauge what
other people think will happen. More often than not, when most people believe something, they're wrong. Like you said, at the bottom people are too scared to buy. At the top, I find people are usually too greedy to sell. It's a whole fear/greed cycle.