These days, car journeys are fairly essential. As is walking down the street and crossing roads. Trampolines...not compulsory
AnyFucker - I agree, trampolines are not compulsory! Neither are skateboards, bicycles, skis, snowboards, rollerblades, surfboards, scooters, horses, gliders, mountain-climbing, hill-walking, bungee-jumping, motorbikes, planes, trains and automobiles ...... the list goes on and on. They're all great fun though!
Cotton wool - aahh, now there's a thing. If only there was enough to wrap up everyone to stop them living life and just let them get fat and unfit. Bones wouldn't get broken, but they would become very soft and weak. Skin wouldn't get grazed, but it would grow pale and pallid. Everyone would die of boredom and/or heart disease. 