Now, flow is a type of intrinsic motivation, that is, there you do what you're doing primarily because you like what you're doing. If you learn only for external, extrinsic reasons, you will probably forget it as soon as you are no longer forced to remember what you want to do. Nor will you be motivated to learn for its own sake. Whereas if you are intrinsically motivated, you're going to keep learning as you move up and so you are in this lifelong learning mode, which would be the ideal.
Via Nik Peachey