I had a chance to speak with someone on the U.S. Olympic archery team about six years ago when my two young sons were first starting archery.
At that time there were interested in Olympic recurve.
One son asked the fellow how long it took, in his opinion to get 'good' (worded as a 9 year old would).
The fellow said that he figured it was 10000 shots before he became confident in his ability.
Now this is extreme, but he went on that afternoon to shoot a perfect 120 in his competition...so I guess he knew what he was talking about