I agree that people don't necessarily choose unhappiness as the alternative, just that they aren't choosing happiness over everything else.
If I instill nothing else in my children during their childhoods, I hope that they learn that it's always okay to feel their emotions whether it be elation or despair, and that they're always able to be grateful for waking up that day, or having a warm home, or food in their tummies and to be grounded/humbled by their gratitude. I feel like those are the backbones of a happy life. Definitely things that I'm learning at 30 and that RAH is struggling to learn now in his 30s.