"The Devil You Know" is a phrase that suggests it is often safer to stick with familiar situations or people, even if they are not ideal, rather than risk the unknown. The idea is that the known challenges may be more manageable than the potential difficulties that could arise from new experiences or relationships. This expression highlights human nature's tendency to prefer comfort over uncertainty. It reflects a common dilemma in decision-making, where individuals weigh the risks of change against the security of the familiar, often leading to a reluctance to embrace new opportunities or challenges.