I think a psychologist might say your personal "hardwired" "baseline mood" is what the majority of the population would regard as "sad," and that you have found ways to live above that baseline. Your brain/body wants to return you to your baseline, and that is what you feel.

(I'm a psych patient, not a psychologist. This "baseline" idea is a topic for discussion with someone working in the psych world.)

If you've found ways to live above a depressed baseline - more power to you!