Not these days. But back in my middle school years I ran a masterful operation of selling overpriced candy that I would buy at the convenience store near my house on the way to school.
Not now, but when I was working full time and going to college full time with two children by myself I bought and sold laptop computers on ebay. This is when ebay was young and almost all users were individuals rather that today where most of ebay is composed of businesses and is no fun at all. I had so much fun with the computer thing. I made money, not a ton but enough that the effort was surely worth it. I stopped the computer thing when I graduated college but soon started grad school and tried to start up again, but law school didn't leave me time to even sleep, so my little business was gone for good.
Sometimes I train working dogs - herders, trackers and security then I teach the people how to work with the dogs. Sometimes it is harder to teach the people than the dogs. Cheers!