Don, you get old at age 68. My logic is that if you had a child at age 18, that person would be 50, the age they qualify to join AARP. Here's the link to an essay I wrote about this in 2022.

https://medium.com/crows-feet/i-did-the-math-and-the-formula-i-created-confirms-when-you-are-old-25cbb653a5dc