The phrase "the last straw" refers to a final event or action that causes someone to reach their limit of tolerance or patience. It originates from the saying "the straw that broke the camel's back," which illustrates how a small addition can lead to a significant outcome. This expression is often used in everyday situations to describe moments when someone can no longer endure ongoing stress or frustration. In various contexts, "the last straw" can apply to personal relationships, work environments, or any situation where cumulative stressors lead to a breaking point. For example, if a person faces repeated annoyances from a colleague, one final incident may trigger an emotional response, making them decide to address the issue or leave the situation altogether.