Most big inventions were made by people in their 20's. If what you say is true those people would then go on to make even more big things in their 30's, 40's, 50's etc, but that doesn't seem to happen. Rather it seems like they explored the topic early in life and then stopped exploring and just continued looked at the world from the same lens as they got older.
Edit: Also all of Microsoft, Apple, Facebook, Google and Amazon were started by people in their 20's. That is a pretty big coincidence, especially given that younger people have fewer connections and less money than older ones and therefore should in theory have a harder time starting a company.