There could be several reasons why humans get upset easily. It could be due to unresolved emotional issues, past traumas, lack of emotional regulation skills, or a general sensitivity to stressors. Some individuals may have a lower tolerance for frustration or become easily overwhelmed by daily life stressors. Additionally, external factors such as high-pressure environments, critical feedback, or conflicts with others can also contribute to easily becoming upset. It is important to remember that each person is unique, and their reasons for getting upset easily can vary.