1. They think they can swim
2. They think they can float, thus pretending to swim
3. They think they are deficient if they cannot swim at the deep end.
4. They wanted to try (at the deep end).
5. They were given help. But they were too good to accept it.
6. They never bothered to check the sign that said “Deep End”.
7. The Lifeguard jumped in to help, but they struggled and kicked so much, the Lifeguard was shoved away.
8. Their swimming instructor did not teach them well enough, even though the rest of the class did fine.
9. The currents (in a swimming pool) were the one that pushed them to the deep end, or away from the guiding walls.
10. It wasn’t their fault, the deep end was too deep.
Take this literally?