Ever walked into a grocery store for milk and walked out with a cart full of stuff you didn't plan to buy? You're not alone.

Do celebrities really die in three? Actor Malcom-Jamal Warner, singer Ozzy Osbourne and professional wrestler Hulk Hogan died in late July, prompting Google search around the “rule of three” to spike.

This rhetorical concept posits that three is the lowest number where humans begin to recognize patterns. As such, it serves as the backbone for effectively conveying ideas and stories, whether it’s as ...