I had plans for Saturday, which included getting a lot of things done. Reality and plans don't always meet, not even halfway.
Our cat is an indoor cat, with a cage on the front porch accessed via a cat flap. When something spooks her or she suspects 'an invader' in her territory (our entire yard even though she's never been out there) she barrels through the flap at a million miles an hour. She finally hit it too hard one too many times the other day, and broke the hinge. A 20cm square hole in the wall in winter is not a good idea.
The issue with replacing a cat flap is that there is no industry standard size. The hole in the wall is a particular size, but it's not exactly easy to pop the wall into your handbag to take down the local pet store. And the hole is three dimensional, adding a measure (!) of complication.
Still cat flap was purchased and installed, after some perfectionist faffing about (and not by me). However, it took much longer than anticipated and that's when my plans to be productive were effectively ditched.
I also test drove a potential new car.