Okay, I now have a couple of different mastodon ids. If I understand mastodon correctly, the fact that I have @brainwagon does not (for instance) mean that if I move to @brainwagon, I'll be able to get it, or perhaps more annoyingly that someone else might grab it and create confusion. This profusion of instance supplier is apparently a sword which cuts both ways.

Sad. Looks like they aren't going to let me have an animated GIF as my avatar.