Prepositional palaver ….

Q: Why does Mr. Squid swim “up to the top” and not “down to the top”?
A: Because if he were already at the top, he wouldn’t need to swim up.
Q: Why?
A: Because he’s below the top, not at the top.
Q: But why does Mr. Squid swim “down to the bottom”?
A: Well, if he were already at the bottom, he wouldn’t need to swim down.
Q: But why does he not swim up to the bottom?
A: Because … the top is up … and the bottom is down.
Q: Why?
A: I … I don’t know how to answer that.
Q: Why?
Q: Did you brush your teeth yet?