Most people, by "100% certainty", mean "certain enough that for all practical purposes it can be treated as 100%".

Not in the context of discussions of omniscience and whether pachinko machines have free will :-/

that makes people say everyone on the Internet has Aspergers.

People who say this should go back to their TVs and Bud Lights and not try to overexert themselves with complicated things like that system of intertubes.

I am aware of that, thanks.

However, in this particular discussion the distinction between certainty and something-closely-resembling-certainty is actually important, for reasons I mentioned earlier.