I picture my brain as a pipe. Words flow down the pipe. Ideas flow as well, but they're chunkier, more substantial things, and every so often an idea, in its course down the pipe, will wedge itself into an awkward position. Words begin to back up. Eventually the pressure pops out the idea, and the resultant splatter just isn't pretty.
For example, armadillos.
X365 is about people you've encountered in your life. I've never met an armadillo.* I bet they're mean. But I saw one on television the other day and knew, as soon as the idea of an armadillo entered my head, that it would get stuck in there. I couldn't get over the thing's appearance - a collision between a pig and a loaf of pumpernickel - and I knew that its awkward shape could not possibly fit in my brain. I also knew that at some point, I would be compelled to write about it, or engage someone in conversation on the topic. Otherwise, I'd spend days unable to write, waiting for the thing to dissolve.
So if I ever meet an armadillo, I'm going to pointedly ignore it. Just because. And anyway, I've got meerkats to admire.
*As far as I know, armadillos are not people. As far as I know.