I didn't think it through.. oh well. I was thinking how long a human life span is.... maybe less then 100. Then wondered how long a human generation is. It's only 20 to 30 years. WHOA! I didn't figure the reasoning correctly - for a generation is from birth to adulthood to giving birth. That was a head spinner. So I kept reading and it takes 3 or 4 generations to span 100 years.

I checked with my son and his first child was born when he was 27. So he is within his 20 to 30 year span.

Being a Baby Boomer and having my first child at 19, my generation starts earlier then20. This has given me something to think about. 8-)