There are three general ways to transmit a memetic parasite: parental transmission, educational transmission, and social transmission.
If your parasite can’t be transmitted parentally, it’s really not much of a parasite. Children learn the basic principles of reality and morality before they are six, and—as the Jesuit proverb goes—anything that can slip in at this age is likely to stick.
Over multiple generations, educational transmission outcompetes parental transmission.
In the more recent past, the Allied victors eradicated militarist traditions in Germany and Japan through their control of the educational system. Furthermore, by treating the press as an educational institution, we can create a system of continuing, lifelong reinfection in which parasitic memes are omnipresent.