My favourite type of posts is the ones by people signed up in one instance, posting in a community hosted by another instance about how they don't understand how they are supposed to make use of federation. And then often still not getting it when people from all over the web tell them that they already are.

It makes sense though - federation is sold as a feature for users, but when done right the users should hardly notice it at all. So of course people end up a bit confused.