Comment by FredPret

I would add exercise and sunshine.

But yeah, our ancestors lived in constant danger of getting eaten by sabre tooth tigers, freezing in the snow, catching maalria, and, in general, watching terrible things happen to their tribe.

They had no therapy, no supplements, no self help section on the cave wall art.

They were forced into a continual outward focus with no time for navel-gazing.

They carried on through all exigencies, and succeeded mightily.