Three men, two brunettes and a blond, are being chased by a tiger through the jungle. They get to a river and have two choices: 1. Get across the river without being eaten by pirannhas or 2. Get eaten by the tiger.
They spot a genie and the genie says I can grant you one wish..

The first blond man thinks “I wish I can get across safely.” He swims across and makes it without a scratch.
The second blond man says “I want to be even smarter than the first man.” He climbed onto a raft and paddled across.
The brunette thinks “I want to be the smartest of them all”. Instantly, he turned into a woman, and she walked across a nearby bridge.