Right, once you do a job you never look at it the same. By hiring it out you never know the details. The same quality of work might look better to you if you didn't do it, but it may be more satisfying if you do.

I think that's a property of having experience doing something, rather than of having done that particular instance of it.

For example: I re-did some grouting in my bathroom, and only after that started to notice the imperfections in other areas not by me. Bits of tile I'd seen everyday for a years, that only after I had experience grouting I realised had grout smeared over them and let to dry.

Well, it's true that homeowners sometimes bite off more than they can chew, but that's not really what I'm talking about. Even if you do a great job, the minor imperfections are going to be very noticeable to you. Whoever did the staircase in my house splashed woodstain on the white paint parts (it's got white for the front of the steps and natural wood on top) and I never even noticed until I did basically the same thing to the side of the house staining the deck.

Also, if your house is in the right area people will buy anything.