neural pathways we don’t use die off over time. What makes our brains hold on to these pathways — and create more — is not simply repeating the same things we’ve learned over and over again, but continually taking on difficult problems.
“I think in 50 or 100 years time we will have discovered the entity that is consciousness,” he told me. “It will be taken for granted that it wasn’t produced by the brain, and it doesn’t die when you die.”