Last night I was trying to decide where to plant some flowers. There were some restrictions - for one thing, I didn't want any plant to be hidden behind a taller one. The morning glory had to go next to the railing, so it would have something to climb. Identical plants should be adjacent, but similar colors shouldn't be. And something conspicuous should probably go in front, so no one would trample the flowerbed by accident. Obviously this was a constraint problem, and one too hard to solve in my head. So, trowel in hand, I set about figuring out how to solve it by machine.
It is a valuable habit for a programmer to hand any problem over to a program at the first sign of difficulty. Or at least it's valuable when you're sitting at the keyboard and already know how to solve the problem. Unfortunately I've never actually done constraint programming, and nothing in the garden proved helpful. So I was still trying to figure out how to explain the problem to a computer when I noticed it had gotten dark, and I had only planted a few of the flowers.
Real programmers can build constraint solvers out of dirt and weeds. I, on the other hand, got to plant my flowers in the dark.