Sims noted that people love sharing the story about how he and his cofounder, Ryan Bubinski, built the product for Codecademy a few weeks before Demo Day at Y Combinator and still found dramatic success. However, he told the audience it wasn't nearly as easy as it appeared, and shared the numerous challenges he faced.

Here are some of the fun stories behind how Sims taught the world how to code, and the lessons we can learn from them: