Why do serious people sometimes giggle?

Normal people are thoughtful. When they have thoughts, they have emotions. When they have emotions, they must show them. When they are completely depressed, they will suppress their mistakes. It is human nature to be happy or unhappy. Hippie-generally refers to a person who is not serious. They are unstable at work and giggle at people around them. Such people disgust the people around them. They are a group of people who are laughed at. However, serious people sometimes giggle, which shows that people have two sides. Serious and not serious are relative. Serious people give people a sense of stability and respect when dealing with problems. They sometimes giggle, which shows their cuteness. It is normal that human nature is multifaceted and inconsistent.