Most people install a cat door so their cat can go in and out without bothering the humans to open the door for the cat instead. However one cat has other ideas how to use a cat door.
This particular cat likes to jump up and pull down on the handle to open the door. Then once the door is open, the cat calmly strolls through its cat door. This leaves the door wide open for the owner to close, inconveniencing the owner, which is something cats specialize in doing on a regular basis.