My dad possesses great powers of concentration, a very disciplined nature, and a puckish tendency to become obssessed with projects.

Sometimes very useful projects, as when he used his architectural know-how to redesign the back-end of our house (hey presto changing a dusty pale lemon storage room into an airy, parquetry-floored den).

Sometimes projects for our benefit, as when he spent a night helping me craft a no more than 6inch-by-6inch-by-6inch vehicle that would keep an egg-stronaut safe even when thrown out a third floor, science class window: My ever-so-practical solution was to stick the egg in a hole cut out of the middle of a huge car wash sponge; his was to bend and tape wire hangers into this complex cube and then suspend the egg in the middle with a harness of rubber bands. The pavement in front of our house was coated with egg mess before he found just the right level of tension to set the rubber bands at. I remember looking at all those streaks of white the next morning as I walked to my carpool car, carrying my spongecraft. The cube was too much his for me to think about using it. Plus the sponge was so fun to squish.

And sometimes very round projects. Once he spent an entire Saturday afternoon figuring out how to draw a circle on an Etch-a-Sketch (the secret: trace a Play-Doh lid). We felt very bad erasing his work once he completed the circle, but there was only so much fun to be got out of showing it to each other over and over. He himself didn't care. The joy for him was in having drawn the circle in the first place.

Another time he was dishing out ice cream for dinner, and he decided he was going to make me a perfectly spherical scoop. After much patting and poking with spoons, he did, indeed, create a perfectly round scoop of ice cream...which immediately rolled away from me and onto the floor under the table.

I mean, it was round. That's what round things do.