Fairly simple question, in Fallout 3, your character pretty much leaves the vault and goes into the world. In that world, he runs, jumps, and... swims? how does the character in Fallout 3 know how to swim, they make no mention of a swimming pool in any of the vaults, and you are not born with the natural talent, so how does the Vault-Dweller know how to swim like a fish?