Software developers get a bad rap. People think we're opinionated, because we blindly adhere to technology decisions we made last year. They think we're dogmatic because we attribute every problem with their software to a lack of pair programming. They think we have no idea what we're doing because we refuse to provide any level of estimate when presented with a problem. Unfortunately we as an industry reinforce these perceptions all too frequently. We value our opinions to the point that we can't see other's points of view. We work hard to deeply understand a technology and then can't separate ourselves from it when evaluating solutions to a problem. We delay difficult conversations until the point where we're unable to have them in a healthy manner. I've held firmly to many fallacies in my career that have kept me from truly reaching my goals and that of my clients. This talk will explore the most painful and common ones that I and others make on an all too frequent basis. Hopefully, attendees can avoid them or at least be self aware and understand the impact that they have on others.