Back in in high school, I worked as a house painter, I guess for a little over two years. I don't mind the interior jobs much. Ceilings can suck, but you can get 'er done pretty quickly if you have a big enough roller. I used about a 24-inch roller, so it's possible to do some serious damage with that sucker. The hardest part is when you start you have to paint around the edges of the ceiling with a brush, to keep from smearing ceiling paint on the walls with your roller. What really sucks is painting external siding with a brush. But, I was able to knock out Scotley's little bitty (doll) house on Citiizen Street in Jonesboro with a brush in just a little over one day.
The difference was that on the first job I mentioned, I was working for my dad who was a painting contractor (now retired), so I had access to all of his equipment. On the job for Scotley, I was flying solo, and I never bought a great deal of equipment. Dad would have let me use his stuff, I'm sure, but I didn't think about that, and I kinda wanted to do it all on my own, anyway.