He took a nap in the jogging stroller (which we are very glad we had the presence of mind to bring). We heard a little music. There was no book fair that we could find. R. saw the poster stuff (Flatstock). All in all, a raging success for an outing with a one year old. Oh, and we ran into a family we usually run into at Bumbershoot (altho we did not run into the other couple we usually see, but they don't have kids, so they were probably in venues actually seeing/hearing stuff), and got to hang out and chat, because child care came with us. Lots of fun.
I realized, after I'd been there a while, that Bumbershoot always stresses me out for a variety of reasons. But I stayed very conscious of it this time, which helped me deal with it (child care is also completely angelic, and very helpful at keeping me calm).
Major items forgotten: baby sun hat and sippy cup.