No kidding! It always feels weird when you measure things in percent of your life, like: 17% of my life ago, I wrote some Ruby scripts to help move from vB to Discourse. And I can still remember some of the trade-offs I made, and why they might or might not matter over time.
I started measuring time in that way about four years ago when I started wondering why time seems to move much quicker now than when it did when I was younger