The purpose of life is whatever you give it. At the end of the day, nobody will remember you, and you will be forgotten.
Absolutely, and I think not enough people understand or internalize this.
I think there are two responses to this - one is that the grand cosmos will not remember me, but my children, friends, and those I can mentor and teach will. You may not remember your great grandparents, but your parents do, and their influence influences you.
The second is that it takes a whole crew to sail a ship - I'm not the hero of the story, but my efforts can help accomplish changes I think are worthwhile in the world. I won't see the end of the journey, but I can help it along the way.
My city made a huge family tree database and I traced back all my anscestors to the 1500's of one branch and around the 1600's of another. It was fascinating to see I had lineage to the Polish Baltics, Northern and Southern Germany, England, and French Canadian as well.
What was a revelation to me was, I never heard of these people from my family. The only significant contribution to my life these people honestly made was the simple fact that they reproduced. I had no connection, identity, or care for who they were.
So in all, it truly made me realize, life has absolutely no purpose, and your contributions most likely won't even be permanently valuable. The only true sense of permanence that one can contribute to humanity is reproducing, and hoping your offspring will do so as well.
If you're born of the working class, chances are you will stay there unless you can figure out a way via labor or relationships to get out. More often than not, people don't/can't.