Concept
Circle of Competence
4 books in the library reach for this idea - each in its own way. When independent authors converge on one concept, it usually deserves attention.
Poor Charlie's Almanack
How this book uses it: Define what you can evaluate reliably and place unclear opportunities in the too-hard pile instead of forcing a verdict.
The Education of a Value Investor
How this book uses it: Only invest where you have genuine understanding. Admit what you don't know.
The Great Mental Models Volume 1
How this book uses it: Know where you have real expertise vs. where you're dabbling. Decisions outside your circle require extra caution or outside help.
The Warren Buffett Way
How this book uses it: Only invest in businesses you genuinely understand. Expand it slowly through study, not by fooling yourself.
