The silliest argument ever

What is the silliest argument two people (or more) can have?

It’s the one that concerns the future. When they’re acting like prophets.
Our predictions are not statements of what will definitely happen in the future. They can’t be. They are merely our guesses.

Our guesses can be accurate. But if they can be accurate it also means that they can be inaccurate.

None of us is able to rule out, with 100% certainty, a plausible scenario offered by our adversary.