I think a human being is like all the substances of life. Time can tear down. One is always competing against nature's cruel indifference. The tough stuff that happens can eat at you year after year after year and if you are not made of strong and smart stuff to survive you falter like Sisyphus, punished for his human frailty, trying to push that boulder up the hill. It becomes ultimately impossible and you just succumb to the forces of nature against you. I think that is an apt metaphor not only for me but for many of those for whom the advantages in life did not always fall their way.
Yes, life is hard. For some it is extremely hard and it takes its toll. BUT the human spirit is resilient and creative. One can lead that "purpose driven life" said by Pastor Rick Warren -- a person who is most definitely NOT my political ally but nonetheless has some worthy thoughts to consider.
I am prodded to ultimately leave behind good works and words; deeds and thoughts that count to make the lives of others better and to know they are not alone.
I am reminded of Don McLean's song: "Vincent" pasted here and at the link. I always loved that song as it spoke to me - http://www.youtube.com/watch?v=dipFMJckZOM. It may speak to you too.