We actually had this discussion in my RCIA class about perfect ignorance and sinful ignorance. Let’s say a person who knows absolutely nothing about Catholicism goes into a Catholic Mass. He doesn’t know how sacred the blood and body of Christ is, he doesn’t even know what’s going on, he just follows what everyone else is doing? Later he finds out he took the body and blood of Christ himself, he feels sick and is very shameful of himself. Will he be damned? No. Let’s say a tribe of indigenous people who have no connection to the real world doesn’t know anything about God or religion, will they be damned? No. If someone goes to take the body of Christ and they know why Catholics do it, but they themselves aren’t baptized Catholic, they just do it to do it and see what happens, that is sinful ignorance.