@ossobuco,
The Universe is 15 billion years old. A hundred thousand years is 0.00001 of a universe life time (a very short time indeed).
Yet in a mere hundred thousand years nothing about my insigificantly short little existance will have had zero real effect on the universe. I will be wiped from memory (and quite likely my species will be wiped from memory). My accomplishments will be nothing. Even how much plastic I dropped in the environment will be forgotten.
The idea that I get 80 years to exist... and then nothing, may be from all evidence, true-- but it bothers me. There is probably no rational basis for any meaning to our lives except for some randomly occurring chemical reactions that believed themselves to have consciousness for the brief instance they occurred on a some insignficant spec of dust in the vast univserse.
The idea that my atoms may be useful to some worms before our insignificant little planet is snuffed out by an expanding (soon to be extinguished) sun doesn't make me feel any better.
Any attempt to ascribe meaning to life is religious in nature and unsupportable by rational thought-- whether or not there is an alleged deity involved.