Even if it does, it doesn't know that it has. And in principle, you can't know for sure if you have or not either. It's just a question of what odds you put on having learned a simplified version for all this time without having realised that yet. Or, if you're a professional chess player, the chance that right now you're dreaming and you're about to wake up and realise you dreamed about forgetting the 𐀀𐀁𐀂𐀃:𐀄𐀅𐀆𐀇𐀈𐀉 move that everyone knows (and you should've noticed because the text was all funny and you couldn't read it, which is a well-known sign of dreaming).

That many people act like things can be known 100% (including me) is evidence that humans quantise our certainty. My gut feeling is that anything over 95% likely is treated as certain, but this isn't something I've done any formal study in, and I'd assume that presentation matters to this number because nobody's[0] going to say that a D20 dice "never rolls a 1". But certainty isn't the same as knowledge, it's just belief[1].

[0] I only noticed at the last moment that this itself is an absolute, so I'm going to add this footnote saying "almost nobody".

[1] That said, I'm not sure what "knowledge" even is: we were taught the tripartite definition of "justified true belief", but as soon as it was introduced to us the teacher showed us the flaws, so I now regard "knowledge" as just the subjective experience of feeling like you have a justified true belief, where all that you really have backing up the feeling is a justified belief with no way to know if it's true, which obviously annoys a lot of people who want truth to be a thing we can actually access.