People might try to enjoy life more while they can. People would think more short-term and less long-term in terms of accomplishing things, having fun, their diets, activities that can affect joints and cartilage, etc. People might get married or into committed relationships sooner. People might have to have kids sooner which would be encouraged out of necessity. Dying early and not living a full life/until old age would have a different meaning. Someone might not care if their risky hobby kills them in their 20s or 30s because they only expected to reach their 40s anyway and not their 70s or beyond.

I guess there would be no retirement.

It would mean that the mischiefs are squeezed in in double density and the joys too. I'm not sure I would survive that.

We’d probably marry and have children a lot younger if that is what we had in mind.

Oh god the 'when are you getting married' harassment would start at like 15 at the latest

Slightly higher quality of life, more sadness, slightly less pleasure

Probably we'd be more terrible.