I'm in my mid-30s with a partner that also doesn't want kids, saved probably 80% of my takehome for 5-6 years, and leanfire is within reach so it's doable. I don't need much, my main interests are cooking, learning, biking, etc. It's been a godsend as I developed a mobility issue and have to take time off to heal. I'm naturally frugal but had I not been intentional about planning for my future I would be in a bind. YMMV.