There were three blondes on an island and they didn’t know how to go home.  A genie came along and granted each of them a wish.

The first blonde said: “I want to be smart enough to get off the island.” So she swam back home.

The second blonde said: “I want to be smarter than the first blonde!” So she built a boat and went home.

Then, when the genie asked what the third blonde wanted, she said: “I want to be smarter than all of them!”

So she walked across the bridge!