Anything that is in the world when you’re born is normal and ordinary and is just a natural part of the way the world works. Anything that’s invented between when you’re fifteen and thirty-five is new and exciting and revolutionary and you can probably get a career in it. Anything invented after you’re thirty-five is against the natural order of things.
Adams is well known for seemingly silly statements that are actually pretty profound. This one isn’t silly and may not be profound, but it sure seems true.
Related to that is a thought of my own which is simply that an event which happened before you were born feels like ancient history and has about the same credibility as a good rumor. Yeah, I know not strictly true–but it helps me keep perspective when talking about events like the Viet Nam war. Very real to me, but mostly just pages in a history book to my kids. Ancient history to their kids.