"You'll never know the difference in 100 years"

Papa used to say when we would get upset or mad over things.

To which a 5 or 6 year old once responded, "But Papa, we never the the difference a hundred years from because we will be dead."

Papa replied, "Some things matter enough that they will last more than a hundred years and those are the only things worth getting upset over.  Everything else is just a passing thing."