Core Insights - The concept of consistent, modest investing can lead to substantial wealth by retirement through compound growth [2] - Low-cost index funds facilitate this process by minimizing fees and friction associated with active management [2][3] - Dollar-cost averaging reduces timing risk and promotes a disciplined investment approach [3] Where the Advice Holds Up - Consistent investing over decades allows modest weekly contributions to grow into significant portfolios by retirement [2] - Broad diversification across thousands of companies makes this strategy largely hands-off, requiring only periodic reviews [3] Where the Advice Breaks Down - Starting to invest later in life significantly diminishes the compounding effect, potentially resulting in less than half the portfolio value at retirement compared to starting in one's twenties [4][7] - Inflation, projected at 2% to 3% in early 2026, will erode the purchasing power of a million dollars over 30 years, making it less valuable than it appears today [5][7] Human Behavior and Investment Consistency - The primary challenge to successful investing is human behavior rather than market performance, as financial pressures can lead to paused contributions [6] - Missing even a single year of contributions early in a career can result in tens of thousands of dollars less in retirement wealth [6][7]