For some reason we constantly feel the need to attach meaning to everything that happens in our lives. In our minds every situation, every experience or any simple act has to mean something.
She sent me a message so that means she cares. My husband brought me flowers so that means he loves me. My boss congratulated me so that means I'm good at work.
By "inventing" meaning we can explain -almost- everything that happens around us, thus we can more easily "control" our lives.
However things are not that simple. There is not only one way to interpret an event. One hundred people can draw one hundred different meanings from the same situation. That's why there is so much arguing between us about everything. That is even why eyewitnesses are not always reliable.
In addition, people can become really passionate about defending their opinion cause their meaning matters. Their meaning is basically who they are. It is based on their experiences, knowledge, emotional and psychological state, intelligence, etc.
It seems that meaning is so vital for us, to the point that I believe that the meaning of life is creating meaning...