Have you ever stopped to think about events and consequences? Think about your life, your metabolism. Think about all your gut flora. Billions of tiny, single-celled organisms living inside you at all times, helping you digest your food and making your immune system more robust.
Think about everything you've ever eaten. All the plants, all the animals. All those glucose chains, all those proteins that your body needs for fuel and building materials. All from other things that died so that you may live. Everything you've ever eaten came from a living thing. Something unique and beautiful, unable to be duplicated, or brought back. A living part of out biosphere, and indeed, our universe at large.
What about your ancestors? All the people who shagged, mixed genes, passed on genetic knowledge, on and on and on, resulting in you. All the things they ate, all the life and death over eons, long and long ago, from the beginning of life upon this planet. Every breath you take brings oxygen to your body, a vital process to your living metabolism. Every breath of air, every atom of oxygen, has been through countless plants. Trees, moss, shrubs, stinging tree nettles, oceanic algae, et cetera. Most of those tireless beings are dead now, having lived long lives in unknowing service to you and I.
Every moment in the visible universe, from the very beginning of time, has had consequences. Things happening that affect other things, those effects going on to affect other things, and so on, ad infinitum. That means that you, being alive, here, now, at this very moment, is a consequence of every event in the known universe, from across all known time.
The entirety of all things known and imagined, the life and death of every living creature on this planet, past, present, and future, has conspired to put you here. How could you waste that?
Can you contemplate what that is worth? What YOU are worth?
Have you imagined that the very placement of the stars could have had a hand in your having been created, long and long ago? It could be that your ancestors could have looked into the night sky and thought, looking upon these celestial jewels, "Tonight is a good night to make fuck." And then totally boned.
Do me a favor. Next time you feel worthless, next time you want to die, next time you wonder if all this has a point, think about the uncountable trillions of creatures that died to put you here. Think about what their lives are worth. Think about how wrong it would be to piss it away.
If you believe in a God, understand that It did a lot to give you your life. If you do not, understand the staggering chances against such a thing as your life having come into being.

Know that all of creation, all life and death, the placement of every atom, the march of time in what we consider the cosmos, has resulted in this, your life, at this moment.
You are the ultimate consequence of everything you could imagine having happened. You are the longest name in the eternal litany of creation and and change from God's lips.

Don't fucking waste it. You are worth so much more than you know.