I’ve always felt that the best balance for happiness is to make sure you’re near the top of at least one reference group in your life. In other words, be great at one thing, even if it’s just a hobby. Any type of success can provide a psychological safe harbor when everything else goes to hell. And success breeds confidence that can help you power through the harder challenges.
To that I’ll add: Keep a backup. You don’t want to be good at hiking all your life, then pick up an injury that doesn’t allow you to hike and feel like a loser. In the best case scenario, let your activities use different parts of your body and/or brain.
Or whatever works for you. I prefer not to be associated with just one thing.