I had some time and decided to renovate my kitchen. I'm doing everything myself: plasterboard/drywall, flooring, electrical, plumbing, cabinets, painting, etc. I had time to learn the standards and do it all the 'right' way, and I'm almost done.
On one hand it's been incredibly enriching and rewarding. I'll never look at a room the same again. Some areas, like woodworking, also surprisingly required much more deep thinking than I'd anticipated.
On the other hand, I couldn't imagine going through half the nonsense I went though for someone else, especially an ungrateful/fussy/penny-pinching customer.