The complex and often conflated Bayes Theorem was recently simplified using lego pieces on the blog https://www.countbayesie.com. This isn't the first attempt at making the reasoning theory easier to understand, but certainly is more accessible that anything I've seen before.
Bayes' Theorem states: P(A|B)=P(B|A)P(A)P(B) Which is a logical expression of probability (P) given varying combinations of conditions (A&B). Bayesian logic is an elegant way of quantifying puzzles like "I have two children. One is a boy born on a Tuesday. What is the probability I have two boys?"
This theorem may seem trivial or narrowly applicable, but its been used to great effect in the real world. Spam detection in email, finding plane wreckage in the ocean, and treasure hunting all rely on the notion of continually evaluating conditional association (how much does this email look like other emails marked spam?).
If you've not used Bayesian logic in your problem solving, I encourage you to take a little time to understand the process and benefit from its usefulness.