Eagleman explains that neuroplasticity—the brain’s capacity to rewire itself—is central to learning, with early diversification (e.g., multiple languages, sports) yielding broader cognitive benefits than premature specialization. Adults retain plasticity when engaging in novel, challenging activities—frustration signals neuromodulator release essential for change. Time perception distorts under stress or novelty due to denser memory encoding, not actual slowing; intentional novelty can counter age-related time acceleration. Dreams serve a 'cortical defense' function, preserving visual circuitry during darkness, especially in REM sleep. Memory is inherently reconstructive and fallible—especially under trauma or suggestion—making eyewitness testimony unreliable. Sensory substitution (e.g., Neosensory wristband) demonstrates the brain’s ability to repurpose regions across modalities. Polarization arises from ancient neural biases favoring in-group empathy and reward responses to out-group misfortune; remedies include complexifying relationships and language-aware interventions. Practical tools include Ulysses contracts for behavior change and space-time bridging meditation to expand subjective presence.