Vehicles where you are exposed to elements (motorcycles, MTB downhill, motortrikes, jetskis, kiteboards..).
Guitars
DJ sets
Jiu Jitsu
Guitars
DJ sets
Jiu Jitsu
It's like biking, people can trim a quarter of an ounce from the bike/board here and there but the body movements and techniques that you learn now will be absolutely the same 100 years from now.