John in Texas: Perhaps the age distribution of Nathan's list is driven in part by the UK's driver's licence rules back in the 50's & 60's. You could legally ride a motorcycle at 16, but a car licence wasn't issued to people under 18. If one left school at 16 and started work, your only transportation options were public transport or a motorcycle. I rode the bus for a while, but the 90+ minutes each way got old real quick. It's possible some of the "colonies" had similar rules. When I started out in 1958, I don't think there were any age/engine size rules, but I started with a 150cc Vespa Clubman. After I passed the test, I moved up to an Ariel Leader 250. It looked enough like a scooter, my Mom didn't realise it wasn't one. A small car followed, then a BSA A7 (500 ccs) which hauled a single-seat sidecar for a while. My motorcycle ownership ended after I got married in 1964 and I didn't ride again until going to work for Norton-Villiers in 1966.