This is the 6797th most frequent Chinese word.
没事
"没事" means "It's okay" or "No problem."
In this sentence, "没事" is used to comfort someone by downplaying one's own emotional state, implying there is no major issue.
你为什么伤心？没事，我只是想起了以前的事情。
Why are you sad? It's nothing, I just remembered the past.
Here, "没事" is employed to indicate that the situation is safe or free from problems.
快走吧，现在没事了。
Let's go quickly, it's all clear now.
In this example, "没事" reassures someone by stating that there is no harm or problem arising from the situation.