Why don't I write these things down?

I was standing at the bus stop waiting to go into town, and I came up with a really good idea for one of the recent artsparks. I started working out the wording, and by the time the bus got into town I had got it half-written in my head. Then I went to the BookCrossing meeting, went shopping, had lunch, more shopping...and didn't write it down.

And now I can't remember most of it, and I'll have to start again almost from scratch.

The most annoying thing is that I have been carrying a little notebook around with me lately, I had it with me and could so easily have jotted my ideas down. I don't like writing or reading on a moving bus, it makes me queasy, but still...it wouldn't have killed me. Or I could have done it when I got to the cafe.

*kicks self*
*falls over in an undignified manner*