And yet "wartime spirit" is a thing. "We were poor but happy" is a cliche'd phrase for a reason. I'm not going to tell you that you enjoyed your serious illness, but it's not a claim that everyone feels happy all the time (clearly false) or that people wouldn't always change things if they could, it's about what studies repeatedly find from people's self-reported happiness.
That we vastly over estimate how happy success will make us, and how miserable illness and failure will make us. That 6 months after winning the lottery or becoming paraplegic people self-report being equally happy with their lives compared to before. That people become happier when stuck with a thing they can't change, than they do with a thing they feel they can change. That we don't know this about ourselves makes us make choices that make us less happy overall. And that these are surprising results is the reason the talk is worth watching.