Actually, this isn't as self-contradictory as it sounds. It COULD be the case that the person still remembers THE INFORMATION but can't remember which SET of information he was trying to forget.
For instance, he was trying to forget "something" ... an old credit card number because he keeps accidentally using that when buying things. He still remembers the number, but can't remember that he was trying to forget "my old credit card number."
Caption this Meme
