Is this true

Got this from an e-mail, today.

"There come's a point in your life when you realize:
Who matters,
Who never did,
Who won't anymore,
And who always will.
So, don't worry about people from your past,
there's a reason why, they didn't make it to your future!"

i would say there could bee some truth in that , but it is kind of sad,
some times I would like to know the reason , why!