Self-employed people probably do more jobs than anyone else because, although your success depends on you, sometimes mastering one single skill makes that success a little precarious.
I met a person on the weekend at a craft show who was selling a variety of pepper sauces. A family business, they produce and sell these sauces without a storefront operation. In the spring, they will sell different products, taking advantage of the growing season. When he told me he could deliver to my door, he explained that along with the other two jobs he does, he constantly travels around. Delivery in the city would not be a problem.
When I hear this story, and others like it, I think of the saying "jack of all trades, master of none." I don't think it necessarily holds true anymore. I believe that in your life experience, you can master many skills. It is what you do with these talents that counts.
I count myself among these "multi-preneurs" as I have several businesses going on simultaneously. They all benefit one another because of my varied set of skills. It is funny seeing people's faces when I talk about all the different directions my day takes me. But I wouldn't have it any other way. It is this variety that drives me; to know I have not pigeonholed myself by being too narrowly focused.
This is different from having several hobbies. I am talking about ways to make a living. It is also a safeguard against steep declines in your revenue stream. If one business is in a temporary (you hope) decline, chances are, another one is not. However, you have to constantly keep your standards high for all your skills or you will find other people figuratively nipping at your heels, happy to take your place.
Lots of hats? Maybe not so good in your closet, but on your resume? Terrific.