3,000-5,000 hours of practice/playing time. Better start young or else you'll be searching for something that doesn't exist. Every good swing must come out of the dirt one way or another. You can cut down on your practice time with tools like video, Trackman and general knowledge, but you still need to pay the price.
Plenty of guys who practice their life away and still can't make it on tour. Certain genetic gifts must be present to keep your tour card. Anybody can learn to break 80 at their local club. Not anyone can learn to break 70 at their local club, let alone under pressure in a tournament at an important event. If your hand eye coordination isn't good, it will put you at a disadvantage.
Kevin is correct when he asks, did your father play? If not, the odds are stacked against you for successful golf (breaking 80 consistently for most players).