Time is perceived as linear in the physical world.  Minutes give way to hours, hours lead to days which lead to weeks, months, and years.  Through practicing mindfulness and meditation, the perception of time shifts.  You come to see time as non-linear, like a spiral where past, present and future are all present at the same time.

To give you an example, think of a tree that starts out as a tiny shoot emerging from the ground.  This shoot grows more shoots that eventually become branches and limbs.  The original shoot grows into a trunk that continually regenerates new shoots and foliage throughout its life.  Looking at the tree, you see past, present and future all in one.  You may adopt this perspective for yourself, knowing that it is never too late to regenerate or revive yourself in life!