If you can devote substantial time every day to practice and playing then it will be possible. With good instruction you can get down into the single digits fairly quickly because once you start hitting the ball well and eliminating big misses, its not hard to do that. The real work comes in when you have to start shaving off one or two strokes a round when you are already playing amazing golf. Those last few strokes - the difference between low single digit and scratch - are a real beast because your margin for error becomes so small.