There are certain things we can change in our life, but there are also things that we cannot change. If we keep worrying about them we lose our peace, but if we accept them, they stop being important, and we stop worrying about them. What we cannot change and cannot influence no matter what, should not be of concern to us.
People tend to focus and think about things which they have no control over. Why worry about something that worry will not change? Why care about what other people think of us, when we are not even sure what they are thinking about? Why worry about the weather, if we cannot change it? Why worry and feel concerned about other people actions, about which we have no control?