The time frame it takes to learn is different from everyone. On average I would say 2-3 years
before an average trader becomes profitable if he is still in the game, it could just be marginally profitable but still profitable. Most quit after 1 losing year which is actually not surprising. You are competing with professionals plus some amateurs and its like any other thing in life, the pros will dominate and take the market share. You don't see people just randomly picking up a basketball or soccerball on the first day and then dominate the NBA or EPL league. It takes years of very serious training to be in that league and even then only a handpicked cream of the crop plays in it. In the trading world, it is the only "league" where the pros also allow complete amateurs to play in, and more often than not the results are disastrous, but also because since there are always new batches of amateurs, It can still be profitable for people who puts in the work.
The learning process is like this, as a rookie you are probably
going to make all the mistakes in the world. So lets say there are 10 major mistakes and you are going to make all
of it. The longer you stick with it you will have certain "Aha!" moments. But then again 1 aha moment is not going to pay for other 9 major mistakes. Every time you have an aha moment, you will reduce you mistake but 1 and till you are breakeven with 5 aha moments, but still 5 major mistakes. Till the point you get to 10 aha moments, you are practically going to be close to printing money, that is the holy grail everyone is seeking. For one of these epiphanies to occur it may take days,weeks,months or even years depending on the person's talent and hardwork.