Figuring out how I work best was the most important study l've ever done.
Studying yourself is valuable.
Do it as if you're a scientist studying a bug.
You're the bug.
Study yourself by making a bug book.
8X a day, give yourself a score from -2 to +2 based on how you feel.
Also write who you're with, what you're doing, and any other important info.
Every two weeks, review and look for patterns.
What's going on when you're in the minus?
What's going on when you're in the positive?
With this info, you'll know where to focus your time.
For me, it's exercise, family, writing, and adventure.
No matter how tired they make me, I become energized when I do them.
The Bug Book helped me. Maybe it will help you too.