I don't think a helmet is something that comes with experience. I think it's a cultural thing. In the cycling-as-a-sport/hobby culture you see a lot more helmets than in the cycling-as-transportation culture. I rode my bike daily to and from college for 4 years and never even owned a helmet, and never saw one on a fellow student on a bike. I lived in Europe for years and don't recall seeing a helmet on the heads of the many cyclists you see everywhere, going to and from the market or whatnot. I see Latinos here in Indy riding to and from work (I assume, since they are wearing uniforms) without helmets... I doubt that they are new to their bike, they just don't wear helmets.