Using good ol'-fashioned cookies! The JS sets it, and then Rails reads
it on pageload. That way, there's no flash of content for it to load in
after JS loads.
If your first wanted list was created before your first owned list,
then `false` would come before `true` in the keys of
`current_user_lists`.
I both fixed this to be more consistent at the model level, because who
likes unpredictable behavior? But also downstream at the view I
hardcoded that true should come before false, because that's a UI
concern that I want to be encoded in the view regardless of what's
upstream.
