As long as you keep trading and investing in cryptocurrencies, you will find out that there are mistakes you didn't know about or those you took less seriously.
For example, with the recent downtrend in the price action of Bitcoin and consequently that of altcoins, many traders have learnt the importance of learning about market cycles, how to use stop loss, when to buy and when to simply stay on the sidelines. This painful lessons came after loosing lots of money on the wrong trades.
Another mistake that people can't seem to avoid is FOMO. This week, LUNC and coins belonging to the Terra ecosystem have been pumping, but some people are considering buying only now after 70%+ increase. This will make them bagholders when those who had been accumulating for long start selling off their coins.
Investing in cryptocurrencies should not be taken as an overnight path to riches and all mistakes school be taken seriously and avoided in the future.