One often can get the impression that all the "great photographers" had to do was turn, point, shoot and the resulting image would be a world class result - that even their mistakes and poor shots are still highclass photography.
The truth is that the experts also took more shots than they ever needed - even in the film days they would bracket shots (even more so then since they didin't have live previews of the results instantly availible). Some would come back and find a whole roll of film might be a load of duds.
The only limit then was cost - it cost them dearly to make mistakes so they quickly learnt not to make the common ones and I'm sure many would walk by some shots because they could not garantee that they would get the shot to work. These days that is not a limitation in the least - memory cards are dirt cheap and that is a freedom - a freedom to shoot, experiment and be diverse. Sure you still have to learn not to make the common mistakes otherwise you will never progress, but never be afraid to make mistakes.
Also as one gets better you overall level of photography will get higher - whereas once you might have considered any correct exposure to be a good shot you might start to look at smaller imperfections - that whisker missing - that finger just clipped - that angle of focus not perfect etc.... So even though you might be upping you game your keeper rate might still not be much higher
Myself I try to compose, focus, expose and get the shot to work first time every time, but I still make mistakes and I still take lots of shots in the hope that I will nail that perfect shot in the series. Sure it can be disheartening when you come back and only a few shots are really worth keeping but you just have to keep trying. Also bare in mind that somedays you just won't get the right light to shoot what you want to shoot - good light to shoot in makes a whole world of difference to you results - just look at serious landscape shooters who will come back to the same spot over and over just waiting to get that perfect, correct light for a single shot.
Finally remember that online you only ever see people good shots - and never that massive mountain of mistakes
