It was amazing. Suddenly, we were able to both sleep through the night AND have a door guarding against hallway monsters because everyone knows hallway monsters are too big to fit through cat doors. Later, when we had children, the closed door also protected against children that wanted to come and sleep with us JUST BECAUSE and that just would not do, yet our cats could still come and go like little karma chameleons without disturbing us.
When you own your house (or if you’re just very, very casual about the concept of ‘damage deposits’ on rentals) you can do this. It is a good thing.