Me and my past memories

The feeling of the past is something hurting not because it is a sad one but because we miss them so much.
I miss my past especially the time i shared with my school class mate, their expression and the way they act, i don’t no the sweetness in it until is gone
But does feelings wont keep us away from happiness because the present and future matters more than the past,
If a mistake is to be fixed it depends on the present and the future not the past