NYC's ban on smoking in bars, initially met with widespread criticism, became a popular and accepted norm. This shows that effective public health leadership sometimes involves implementing policies that are unpopular at first but create long-term societal benefits.

The opioid epidemic is fueled by a lack of things to do, as community hubs like theaters, parks, and libraries have disappeared. Rebuilding this 'social infrastructure' provides purpose and connection, acting as a powerful, non-clinical intervention against drug addiction.

Major societal shifts, like universal childcare, don't start with national legislation. They begin when communities model a different way of operating. By creating local support systems and demonstrating their effectiveness, citizens provide a blueprint that can be scaled into state and national policy.

The most effective way to spread a new idea is not through expert lectures but through peer inspiration. Kate Raworth found her model gained momentum when teachers showed other teachers how they used it, and mayors showed other mayors. This led her to create an action lab focused on unleashing peer-to-peer learning.

Brady's Chris Brown notes successful public health movements, like anti-drunk driving campaigns, first changed social norms with slogans like "designated driver." This cultural shift made subsequent policy changes and enforcement easier to implement.

Community accelerates personal change in three ways: it helps navigate rapid change through real-time peer support, it makes building new habits easier by removing reliance on individual willpower, and it enables results that are impossible to achieve alone. It externalizes the burden of transformation.

Small, incremental increases in daily walking have a disproportionately large impact on health. Adding just 1,000 steps (a 10-minute walk) can lower the risk of dying from any cause by 15%, reframing health improvements as highly accessible.

Forcing innovations to "scale" via top-down mandates often fails by robbing local teams of ownership. A better approach is to let good ideas "spread." If a solution is truly valuable, other teams will naturally adopt it. This pull-based model ensures change sticks and evolves.

Parkrun's success stems from its inclusive 'run, not a race' philosophy. By removing official course records and welcoming walkers and social participants, the event attracts a broad demographic that is often deterred by the competitive nature of traditional races, turning it into a social gathering.