How Memes Die Out

I remember hearing that the reason why heliocentric theory was eventually accepted over the geocentric theory was because the people who thought the heliocentric theory was true eventually died and the new generation learned the geocentric theory. I think this is similar to religion, the biggest change in the demographics occurs between generations (which is probably why religion is heavily focused on child indoctrination). Although their are some examples where people lose the dogma in their middle ages.