Gaining experience.

When you are in college, it is very rare that you realize the importance of practical things. You might take up a part-time job but you never realize the actual effect of that particular job in your life. If you get a job or even a small internship related to something you ate going to do fir the rest of your life, you cannot even imagine the profit you are getting in doing that job, even if you are paid groundnuts. You gain experience which is the best way of learning.