DY14N, it all matters on how much you practice, really.  I wasn't good at golf at all before high school...I didn't become serious with it until the summer going into my freshman year.  That year, I was a 21 handicap.  I played around 60 times every summer from that year on....because I have a membership at a country club.  I went form a 21 to an 11 the next year, to a 7 the following year, and dropped from a 7 to a 1 going into senior year.
It all depends on how much you want it though, man.  Its a lot of hard work.  I practiced almost every day, on every aspect of the game, and played almost every day...I had a very good teacher essentially rebuild my swing my freshman and sophomore year.
Some people have more natural talent than I did...I am a very good athlete so I was very trainable, but had I not had help with my swing I would have never surpassed a 5 handicap probably.  But keep in mind, the muscle memory never goes away...I have only played about a dozen times this summer and can still play to a 3 handicap.
Good luck with whatever you do.
We'll have you dead pretty soon.