" Company executives fail to anticipate how their rivals will behave because they are focused on their own organization. For example, when a company decides to break into a fast-growing market, it often forgets to consider its competitors are likely to do the same, leading to an underestimation of risk.
Don't be one of the >80% of start-ups that don't reach their initial market share targets! https://thedecisionlab.com/biases/planning-fallacy/
Always good to have it in mind and to counteract this cognitive bias. An excellent and concise article.