Why does my cat follow me into the bathroom?

This is one of the most common and most harmless indoor-cat habits there is. A closed bathroom door is a rare moment when your cat can’t predict what you’re doing, which is enough to make a curious cat want in. It also doubles as safe, enclosed, novel space with running water, echoing sounds and an owner sitting still, all things cats tend to find interesting. For a cat who is otherwise affectionate and relaxed, this is simply attachment and curiosity, not a sign of separation anxiety on its own.