Why You Need To Live In The Present Moment?

I try to live at the moment & always focus on what I do. That way I am not thinking of the past to bring it to present & to project it into the future. The past is a closed chapter for me as I have gone through so many different phases in life that you would never imagine. I haven't seen my family for 20 years. So scarred of living my life alone. Painful but life's experiences have made me feel stronger.