With his resignation Tuesday from the chief executive officer job at Uber, Travis Kalanick joins the pantheon of company founders who've made the difficult move beyond life as their company's CEO, even if temporarily. Some did it by choice: Howard Schultz, Ralph Lauren. Plenty of others didn't: American Apparel's Dov Charney. Men's Wearhouse's George Zimmer. And of course, way back in 1985, the example that must be included in every story about founders leaving their companies: Apple's Steve Jobs.