Research suggests that humans are biased, not-very-rational decision-makers. We believe we see things clearly when the evidence shows otherwise. Throw in a big dose of optimism, and it's easy to see how estimating software projects can be problematic. Our best hope is to construct diverse groups with varied viewpoints.

Sprint retrospectives are often skipped, compressed, or organized in a way that doesn't provide good feedback. This is unfortunate, as a well-planned retrospective is a great way to improve how you work. Good retrospectives enable engagement and safety, distill and prioritize ideas, and create concrete action items.

On any team, there are bound to be some differences. But even though work styles may differ from what you expect, they may not be problematic simply because they are different. Before making assumptions about what a teammate is doing or why, just ask to find out. Their differences may bring a helpful new perspective.