Prudent YOLO I guess! It's strictly true that we only live once, so that isn't the issue.
And I think it's just clearly wrong to say the "longest life" per the letter to Menoeceus.
So we're left with "the most pleasant in subjective terms" i guess!
So maybe even prudent YOLO does not get to the heart of it quickly - I best we can get more suggestions on the right modifier if we get creative - but it needs to be something about the "most pleasant"