You're right, fun is cheap. So why spend my fortune when I could retire early instead? To live each day like its your last is to fear living. I will live my life assuming I live to a ripe old age, and will never fear to live another day. The freedom this has brought me and the peace of mind is something no amount of hedonism could replace.
To assume a healthy savings means I must be a miser is unwarranted. Most who are thin are not anorexic.