Why it's important to love what you do (Work, school, free time activities, etc.).
If you love the things you are doing, being busy will still be okay.
When the times do get rough, you can remember that most of the time you do enjoy what you are doing.
Nobody else is going to choose what you do, so you better pick choices that make you happy.
Loving is conducive to being happy. Being happy generally indicates less stress and greater productivity.
You don't regret the time you've spent when you know that you've put what you really care about in the right places in your life.