Past is dead, future is uncertain and still come to life, only present is live. What is amazing that we like to live with dead thing or think what is still come to live and is uncertain. We forget the present, and when it also become past we begin to remember this with sorrow and grief. When present was here we do not make it better, and only remember the past and waste the present.
Its simply means that we do not want happiness. We only want sorrow and grief.
If we want really and truly happiness we have to shift mentally and physically in the present moment. Or stop speaking lie with ourselves by saying that we want happiness by living in past.
Future is also creates worries and doubts.How uncertainty can produce happiness?