Someone knocking at your door for no apparent reason.
Monk key
Oh, you know. About 5 pounds. I'll show myself the door now.
The knock speeds up.
Crumbs!
To get out-of-range of North Korea's nukes.
To get to the other wife.
Nobody asks, 'who's there ' when you try and tell a knock knock joke.
That I will open the door
There's none. They both knock on the door, but never goes in!
To use the Pokestop.
They don't believe in higher power.
CAT: *bolts for no apparent reason* ME: *bolts in the opposite direction in case she's after both of us*