George Buddy sends an article on "Farming for the fun of it". It's an interesting idea: would anyone write an article on "Bureaucrating for the fun of it". "Plumbing for the fun of it". We make avocations out of some vocations, but not others.
If you visit Oatlands, an old plantation house outside Leesburg, VA, they have a carriage house--full of carriages. At one time, maybe still, rich men liked "coaching", driving carriages instead of their hired help. If you can afford it, I suppose it's different strokes for different folks. But the bottom line, the one that makes the difference as to whether it's vocation or avocation, is whether your livelihood depends on it.