Greg Halpern has opinions. About parking. About handshakes. About the precise moment Costco becomes unmanageable on a Saturday morning. He's fifty-nine years old, a regional logistics manager from outside Columbus, and he has spent the better part of three decades quietly observing the systems that hold life together and the people who refuse to use them correctly. Three Day Genius is his complete guide to everything. He's not qualified to write it. That turns out not to matter.