most mistakes of traders are;
* Having no proper training in the craft to attain knowledge about it.
* Having no experience traders that is good in the craft to guide them.
Not everyone has an access to this so in a way it's not really a mistake on the newbie trader side, some people just started trading and they just gained their own experience through continuous losses and gains and even if they try and find a school that does this exact thing, they're going to get nothing out of that because the market is volatile and they might not even use a lot of the stuff that they've learned in that school when the actual trading happens, mentors are expensive especially if you don't have a connection.
I agree with you Blackhawk because I see some equivocations in his submission even though the entire post is a great one. The first point is a little not clear, maybe the choice of words made it complicated because I don't under how "no proper training in the craft" differs from "attain knowledge". Furthermore, having knowledge is not just enough to succeed in trading as knowledge is just one aspect of it. There are other important things like emotions, personal dreams, challenges and targets that can all play key role in trade execution. Managing these is as important as acquiring technical and fundamental knowledge.
I used to advise people that trading is a long time investment that requires time and resources just like the formal education that is stratified to enable the individual be fully developed. Where traders start having problem is when they expect to become rich within few months of starting their trading career whereas they spent over half a decade in their conventional education yet still not living the life of their dreams. My parting word to young traders is always
learn on the process, grow while doing it and give it time.