Traders are big risk takers so everyone should know what he or she is trading on so that when you loose which is normal, you will learn more.
This does not apply to all traders. Most newbie traders end up as risk takers and most of them get washed away. Those who survive are the professional traders who know how to manager risk and not go all in.
It is not necessary to always profit but important to be in the game. For this prior knowledge of speculative markets is important and knowing the different modes of trading like spot,margin become important. Doing a mid-long term spot trading has low risk and decent gains, but requires patience.
I have lost but I have gained more in trading with the help of research and mentorship programs.
Not necessary at all to go for mentorship or such. You can learn a lot of trading on your own, the key being patience and timing. Learn how to analyse charts, observe S/R levels and place orders according. Do dummy paper trading at first as well to get a feel if you are new.