Key ideas from David Eagleman

• Brain plasticity requires constant challenge - "you got to continually seek novelty" and "constantly find the next thing that's a real challenge for you" - David
• Time perception is memory-dependent: dense memories from novel experiences make time feel longer, explaining why childhood summers felt endless
• Ulysses contracts help future self-control by removing temptation in advance, like locking phones away or clearing alcohol from homes
• Dreams defend visual cortex from takeover by other senses during sleep's darkness, with REM sleep correlating to species' brain plasticity levels
• Empathy circuits activate less for out-groups versus in-groups, even with arbitrary labels assigned just minutes before - "your brain cares much less" - David
• Memory accuracy degrades equally for traumatic and mundane events - even 9/11 memories drifted as much as breakfast memories over time
• Cortex is "a one-trick pony" that adapts to whatever sensory input it receives, enabling sensory substitution like feeling sounds through skin vibrations