Some people stay up late at night worrying about their sins.
I stayed up a bit and worried about this hypothetical situation concerning repentance:
Suppose there was a good Catholic man who was raised in the Church, knew its teachings inside and out, etc. One day, he gets into a horrific car-accident that he survives, but which leaves him incapable of forming new memories. One day, he commits a mortal sin that he does not immediately repent of. For reasons outside his control, he is unable to let himself know what he did on the prior day (say that on his way home he's mugged, knocked unconscious, and is out for the rest of the day, soon after the sin is committed). But he *would have* repented had he remembered what he had done and had repented of similar sins in the past.
Assuming no one involved in such a sin (if any one was) ever told him that he'd done it, what happens? It doesn't seem to sit well that God's grace could not penetrate to this fellow. Is it sufficient to confess past sins with the intention to confess ALL sins? Does he need to feel contrition for THAT sin, or for his sins in general? Hm.