## TL;DR

Personal finance fundamentals: spend less than you earn, invest the difference, avoid debt, build emergency fund (3-6 months expenses), diversify investments. Index fund investing (Bogle, Vanguard): low-cost, broad market exposure beats stock picking long-term. Compound interest is the most powerful force in personal finance. Start early.

## Core Explanation

50-30-20 budget: 50% needs, 30% wants, 20% savings/debt. Emergency fund: 3-6 months expenses in high-yield savings. 401(k)/IRA: tax-advantaged retirement accounts. FIRE (Financial Independence, Retire Early): save 50-70% of income, invest aggressively. 4% rule: withdraw 4% of portfolio annually in retirement (Trinity Study). Credit cards: pay in full monthly — 20%+ APR is wealth destruction. 'The best time to plant a tree was 20 years ago. The second best time is now.'

## Further Reading

- [The Simple Path to Wealth (JL Collins)](https://www.jlcollinsnh.com/stock-series/)