Mistakes are a great thing to learn from and early stage start-ups experience many of them. Some mistakes can be blessings in disguise. I'd love to hear everyone's thoughts and of course possibly some crazy early startup stories

I read "The One Thing" by Gary Keller after it was recommended by someone I follow on social media. While it can get a bit repetitive the overall message to narrow down your focus and put your resources towards a single thing that brings progress has been really helpful to me. It's like a Pareto Efficiency model for the digital age. What book have you read recently that helps you at work?