It takes exactly 479 days, 6 hours and 35.67843 minutes. (Give or take a few milliseconds)
For real though...like Cyrano said, it all depends. Personally it took me about a year to really change my mentality and get results. Everyone is different though and there is never a point where you arrive and say "Okay, thats it I am now a DJ...hooray for me!"
It doesnt work this way. In fact the learning never stops! I still fail miserably from time to time. The difference between me and the AFC is that I have learned to sincerely laugh it off when I crash and burn.
Kind of like learning to ice skate. Do you get all upset and down on yourself when you fall and your friends laugh at you? Or do you laugh right along with them, get up and brush yourself off?
The crux of the AFC is that he takes his own self image wayyy too seriously. Experimentation becomes a scary thing instead of the FUN its supposed to be.
In short...
Trial & Error is the DJs lifetime companion. Learn to love it and you will be flying in no time!