In science there are two phenomena; one is linear and the other is cyclic. A linear phenomenon is one way and not repeatable but cyclic is repeatable. I find almost most of the phenomenon in Nature are cyclic like day & night, seasons, planetary motion, bio-degradation, birth and death etc. When we were born we were not having teeth and were weak; and during old age we will become like a child once again. This proves the point life is cyclic.
Extending this argument Vedic seers say our birth & death is also cyclic which is referred as reincarnation. Veda also proclaims that all are governed by 'Cause & Effect". What we are today is the result of what actions we took before and this fact cannot be denied. Hence what actions we take now will decide our destiny tomorrow. Hence quality of our thought and action are of paramount importance.
We came to this planet not out of our choice and will go away without our choice. In between the brief period called life we have two choices - one is have a positive outlook and make good use of our presence and another always complain and blame everything around us. The later is not prudent as it is evident from nature all creations are active during their sojourn called life. Hence let us make every moment a memorable one.
With whole of my heartNC