I think of the following situation: one person, who had a poor catholic education, but nonetheless is a catholic, when he goes to confession, he does not know he need to state every mortal sin since the last confession, and more or less he confesses as he thinks it is ok in the moment. For example, a sexual sin, he confesses it, but he withhold a certain sin he’s not ready to confess, and maybe he, in a later confession, decides to confess it, but he is very “undisciplined” let’s say, in the way he confesses, due to ignorance. I am from Argentina, I had a very poor cathecism is school, I didn’t know anything about my faith until about 5 years ago. I went to a catholic school 30 years ago. I think that many catholics are in my situation, they don’t know the cathecism. Nonetheless they confess, because I see them in my church. What if they die, not knowing that all the confessions they made were invalid. But by no fault of their own.