If you knew then what you know now

[AK Gerard]

Train once a week if you're busy, or lazy, but don't take a whole week off if you can help it. That constant contact with your school, and momentum is very beneficial.

This times a thousand. No excuses, just show up once a week even when you don't want to. Even when injured, show up and do what you can, even if it's only watch. Otherwise it's way too easy for an intended few weeks off to become a few months (or more).