Many people make mistakes like this despite being said to be old traders, but they don't learn from the many mistakes that occur.
The main problem is not his knowledge but his mentality which really cannot be controlled.
Too FOMO when the price goes up and don't buy again when the price really crashes, even sell at a low price and get a lot of losses.
5 years is not a short time, it is a time that makes a person well shaped by the market and should have good self-control as well as more expert trading knowledge
You are right about the mentality and some are too stubborn to accept that they are wrong and they need to learn more. They think if they have made some trades in profits they are legends but they don't know anything and not accepting their errors can cost them more.
They also fall for every Fomo and they don't care until their wallets liquidated and they got no money, they sell early and don't book profits, for any trader the best practice is to hold coin until the market is good but if we are doing future trading our SL should be placed to save us some money and newbie will be doing opposite, they will be adding more to increase their liquidity range. Still some people don't learn in 5 years and there are traders who became expert only in a year, it depends on the practice, not on the time they have spent.
Exactly, the mindset is a huge part of trading and many never realize how much their own ego and stubbornness work against them thinking a few profitable trades make them legends is dangerous because it blinds them to mistakes and lessons they need to learn.
FOMO is another killer most beginners chase hype without strategy and only realize too late when their wallets are emptied or profits vanish they sell too early or hold too long without proper risk management the smart approach is to wait for favorable market conditions and for futures trading always use stop losses to protect capital. Practice and discipline matter far more than time spent trading some traders become experts within a year because they focus on learning, analyzing, and adjusting while others can spend five years making the same mistakes over and over it’s about quality of practice not just quantity of experience.