We are comfortable in our memories as long as it is satisfying. As a result, we forget the reality that is this present. Many go mad because they never left the past. As a result reality made them crazy. The acceptance is not not easy.
Our life is limited. We have to let go our past for living in now. We cannot mourn for life about someone or some incident in life. With time, everything heals.
Not accepting reality and making peace with past is sign of weakness.