How do I know if I have the skill to be a successful active investor?

This question already shows you're wiser than most. Honest self-examination is the beginning. Zera Yacob taught me that reason applied to yourself is harder than reason applied to the world. So ask: Can you study financial statements deeply, not just headlines? Do you have a track record—not imagined, but actual—of good decisions under pressure? Can you hold a contrarian position without needing others to validate it? Can you accept losses without your identity breaking? Most importantly: do you have time? Active investing demands hours weekly. If you're checking your portfolio hourly out of anxiety, not analysis, you're not an investor yet. Here's the test: paper-trade for a year. Track what you would have bought and sold. Did you beat the S&P 500? Did you do it consistently? Did you stick to your thesis during downturns? If yes to all three, you have something. If no—and most of us are no—there's no shame. Building wealth through indexing and living well is far more dignified than losing money trying to prove you're exceptional.