“…memes should be regarded as living structures, not just metaphorically but technically. When you plant a fertile meme in my mind you literally parasitize my brain, turning it into a vehicle for the meme’s propagation in just the way a virus may parasitize the genetic mechanism of the host cell” ~N.K. Humphrey quoted in The Selfish Gene

I agree that memes should be regarded as living structures in a technical sense. Doing so makes it easier to reason about the phenomenon. 

But I’m not yet convinced that the meme-brain relationship is strictly parasitic. Like I think there’s an argument for certain flavors of memes being a critical component for human brain development (eg scientific ideas, musical tunes, culturally-imbued knowledge)…making the relationship mutualistic