But all I really can ever say is that it is a role that is really difficult to understand fully unless you've done it.

It's more than just enforcing rules black and white. There is a penalty almost EVERY single play. There is always a hold, there is very frequently something you can justify as unsportsman-like, and so on and so on. It's a combo of enforcing rules, maintaining order, playing the advantage, and minimizing your presence. Specific emphasis is always in flux.

My time working on a psychiatric ward seemed oddly similar to my time as a football ref.