I think this might just be the story "S.F." by T. E. D. Klein, which appeared in the "1st Orbit Book Of Horror" in 1976. A brief synopsis, from the Vault of Evil forum:
> This is the tale of how in the future we'll all have metal helmets welded to our heads that cause 'Selective Forgetfulness'. This means people only ever have to own one book and no new movies or works of art are created - you simply forget about what you just read and read it again! Imagine - you could discover Eat Them Alive over and over. At least it would give those of us who never learn an actual excuse.