Why Our Brains Are Built To Forget

“We remember and we forget. Lots of people know that marijuana makes us forget, and researchers in the sixties and seventies wanted to understand how. They discovered that the human brain has special receptors that perfectly fit psychoactive chemicals like THC, the active agent in cannabis. But why, they wondered, would we have neuroreceptors for a foreign substance? We don’t. Those receptors are for substances produced in our own brains.” – Paris Review