Depending on how often you can get out to fly, the time it takes to gain basic control of the kite, which means no more crashing, can be multiplied by three and that's about how long it will take until you can feel the changes that subtle adjustments make to how the kite flies. For some people that's three years; for others it's three weeks. It all depends on how much time you put in on the handles. Of course, some are "naturals" and it just clicks for them. For most folks who get out to fly frequently it takes about two seasons to get to the point where you understand the how and why of what makes it work. To put it simply, there are three stages of flying a kite, whether it is single, dual or quad line:
1. The kite flies you.
2. You fly the kite.
3. Both of you fly as one.
Most people never get to the third stage, or only feel it briefly in certain circumstances when everything is ideal, including mindset. Watch videos of the pros flying. It's easy to see that they are somewhere else mentally and no longer have to think before making a move. It's difficult to explain, a Zen-like state that you will only understand when you've felt it. If you stay with it long enough it will happen, and the desire to have it happen again is what will keep you in kiting. It is an addiction to bliss.