Universality of the UN is a worthwhile thing in its own self because it means that every country belongs, feels it has a stake, and participates, rather than going away and finding other methods of conducting international relations.
Everything that's really worthwhile in life comes to us.
Whatever you remember, or feel, you need to know that whatever they were they did one worthwhile thing in their miserable lives. And that was you. Whatever they were, they couldn't destroy that. They couldn't stop you from becoming.
One thing is certain: you will find plenty of worthwhile things to do. You will not be bored, or lack fulfillment in your life. Most important of all, you will know that you have not lived and died for nothing, because you will have become part of the great tradition of those who have responded to the amount of pain and suffering in the universe by trying to make the world a better place.