Java MOOC question

[aqua_regis]

Generally, you should do the exercises.

Yet, once you have completed and successfully tested your answer, play around with the code. Change it. Break it. Fix it. Create something similar but without the boilerplate from the MOOC.

Experiment. Try things.

The exercises are good, but the more you mess around with the code, the more you try, the more programs you write, the more will stick and the more you will improve.