Maybe? I’ve thought the same about a lot of things covered in the school’s curriculum with former schoolmates or people who went to the same schools in the same district around the same time with the same curriculum; but over the course of my adult life I’ve heard variations of the question “why didn’t we cover this?” about some piece of information (including specific vocabulary) about some subject or another that was covered and I clearly remember being in the textbooks that were used district-wide. Among friends at least I’ve long ago stopped answering that question with “actually, we did”.
People just forget a lot of what they learned in school, but if you re-teach them it might jog their memory of the first time they learned it… or it might not. Pretty much a coin toss.
Quite obviously, almost nothing will stick if simply mentioned/explained just once or twice during the schooling process. Its usage has to be incorporated into the process kind of like when you learn basic algebraic formulae and then apply them countless times during the years to come so they become a thing as ordinary as your own hands. You can still forget precise correct formulae after some years of non-usage but you will never forget they exist and you will always know you have to look up or derive a specific formula once you encounter a relevant problem.
People just forget a lot of what they learned in school, but if you re-teach them it might jog their memory of the first time they learned it… or it might not. Pretty much a coin toss.