You can have a few items on your someday/maybe list like "sort that pile of stuff on the brown desk". The "Getting Things Done" book mentions something like this. So, in a way you have everything in your system, even though in a way you don't.
I started gradually. I carried around a notebook and wrote things into it when they
occurred to me. I'm still doing that. That is, whenever I find myself thinking
"Oh, yeah, I'll have to remember to do X", then I write X into my system.