As an adult do ride your bicycle anywhere? Do you still have a bicycle for that mater or is it in the back shed, all the cable rusted, the chain in need of lubrication and the tires aired up? I have been riding a bicycle for many years, just for fun and exercise. Now I have been riding for not only exercise but transportation as well. Most of the trips that we make to the store or other places are less than two miles from home. With the weather being nice, I have been riding here and there, to the store to pick up a few items, to the auto parts store for small things, to the post office, and other places. I find it is enjoyable and saves on gas money, with the price of gas hovering around $4 a gallon, my Jeep is not the picture of economy.
Cycling is faster than walking, it does not pollute the atmosphere or use any fossil fuels. It is great exercise and even fun. Get out that old bike, go buy yourself a new one and get out there and ride.