This is a humorous and nonsensical statement, likely a joke or a misunderstanding. There's no logical connection between being told there are 400 billion stars in the sky and someone needing to "bench wet" or touch anything.

Here's why:

* "Bench wet" is not a recognized phrase: This phrase doesn't have a common meaning. It's likely a made-up term for comedic effect.

* The number of stars doesn't influence behavior: Knowing the number of stars in the sky doesn't inherently make someone need to touch anything.

* The statement is designed to be nonsensical: This is likely a joke or a playful way to highlight the absurdity of expecting a specific action based on a random fact.

If you heard this phrase in a conversation, it's best to ask for clarification or simply laugh it off as a silly joke.