This has become another annual tradition of mine: going through my journals and lists from last year to find simple nuggets of wisdom. These are the aha's that shaped my year and that I hope to bring forward into a new year. So many of these seem like common sense, but they're good reminders of the basics. Hopefully they spark some learning for you as well. (You can see lists from past years here and here.)
Years ago I read the book The Happiness Project by Gretchen Rubin. In it, she made two lists of statements, of truths, that she lived by. She called them the "Twelve Commandments" and the "Secrets of Adulthood." They contained things like, "Be Gretchen", "Enjoy the process", and "Bring a sweater." These lists felt really important to me, so ever since then, I've been compiling my own lists of learnings to remind myself of what works in life, and what doesn't.