Yes, I am getting old, but I don't think I caught up with you yet.
You're right about EU, and once I painted most of the world orange, I lost interest in playing further. Same goes for CK2, once all of Scandinavia was united and practising Suomenusko, my goal was achieved. Though I'd still like to try and restore the Roman Empire some day. With CK2 you create stories, however, which did make the game a lot more fun.
I'll play HoI...some day.