A probability isn’t a prediction; it’s a contract about the long run. “Thirty percent rain” means: if you could replay today a thousand times, it would rain in about 300 of them. On any single day, reality is lumpy. Act like a portfolio manager: define the sample space, list outcomes, assign fair odds, and make choices that win in aggregate. The mistake is treating a percentage as a promise. The skill is turning that contract into better habits and policies.
