While it is all very well to distinguish happiness that is transient from that which is lasting, between ephemeral and genuine happiness, the only happiness it is meaningful to speak of when a person is dying from thirst is access to water.
Destiny ... a word which means more than we can find any definitions for. It is a word which can have no meaning in a mechanical universe: if that which is wound up must run down, what destiny is there in that? Destiny is not necessitarianism, and it is not caprice: it is something essentially meaningful. Each man has his destiny, though some men are undoubtedly "men of destiny" in a sense in which most men are not.
For the rest of your life to be as meaningful as possible, engage in spiritual practice if you can. It is nothing more than acting out of concern for others. If you practice sincerely and with persistence, little by little, step by step you will gradually reorder your habits and attitudes so as to think less about your own narrow concerns and more about others' - and thereby find peace and happiness yourself.
You want to make decisions that are meaningful to you, and that are going to continue to enhance you being who you really are and what your message to the world is, and everybody has one. The real important thing is to know what that message is and how you want to carry that forward.
Courage becomes a worthwhile and meaningful virtue when it is regarded not so much as a willingness to die manfully but as a determination to live decently.
It is in the twenties that the actual momentum of life begins to slacken, and it is a simple soul indeed to whom as many things are as significant and meaningful at thirty as at ten years before. At thirty an organ-grinder is a more or less a moth eaten man who grinds an organ - and once he was an organ-grinder! The unmistakable stigma of humanity touches all those impersonal and beautiful things that only youth ever grasps in their impersonal glory.