In our dog’s case, it’s because she went blind. She kept walking really slowly everywhere, and one day she walked into the space between the wall and the open door and couldn’t figure out why she couldn’t walk forward.

She’s fine though - she has a fantastic mini-map in her head and never gets lost anymore. It’s uncanny to watch her start to take the correct turns before she even gets to them.

My other blind dog has to be confined to a pen for his own safety though. He’s completely hopeless at navigation and doesn’t understand directional sound, so we can’t even guide him to us by calling him. :(