Take this as your motto to help lead you to make good choices. If you get into the habit of asking it, this one question will lead you to greatly increase your overall efficiency. You will find that your productive use of time (that would otherwise be wasted), will lead to moving rapidly along your road to a good future, while at the same time freeing up other times for just fun! Sounds like a WIN-WIN situation to me!
Think about it. --- If you use the time while going to and from school to do homework, then you will have more free time at home to do other things! When you go to the dentist or doctor, take homework with you. Work while traveling. Work while waiting for the doctor. Then when you get home, you wont have to do so much homework. Your time will be freer.
Keep asking that question. You will find all kinds of opportunities you would have otherwise missed!
Doesn't this make GOOD SENSE?