Some night when you have nothing else to do, take a drive at 3am. If you would always rather sleep, this can be a thought experiment rather than a physical exercise. Try to find a high-traffic road or get on the freeway. If the place you live is anything like the place I live, you'll find a surprising number of people.
It's easy at this time of night/morning to imagine what these people are doing, why they're driving at this hour. That man is on his way to his job in a hospital. That couple is of their way to the same place to give birth to their first child. The teen is on her way home after a late night watching movies at a friend's house. You get the idea.
Realize now that each of them is embroiled in their own story, living a life full of just as much detail as your own. Each one experienced childhood, some happy and loving, some neglectful, some abusive. They went to school and had friends and rivals, favorite teachers and the worst classes. In some cases their lives have extended beyond what you have experienced. They've lost a spouse or fought cancer or watched their body wither with age.
The point is that to each of them their own life is the center of the universe. The everyday stressors and the huge, life-changing events are all so important. This is true for every single person you see.
If you want to really blow your mind, think back to their birth. The parents certainly had profound emotions that day. In fact, that was likely one of those very important days in two entirely different lives, each with its own birth, growth, and perhaps death. The web of near infinite moments and details of life extends back in time, generation upon generation.
Estimates place the total number of humans who have ever lived at over 100 billion. It's easy to separate ourselves from "the other"–people in far off countries with very different cultures, people from the past with low levels of technology. But in fact, their mental faculties, their emotions, their thoughts and lives are very similar to your own. 100 billion people think they're the center of the universe. But they're not.
The truth is that nothing you or I or anyone does is outstanding in the global, long-term scheme of things. There are billionaires and superstars you've never even heard of. Throughout time there have been countless dukes and kings and queens, Ozymandiases all.
Some people look at this and see the miracle of life. Through all of time and space, everything conspired exactly as it had to in order for me to exist. My response is so what? So I can worry about that $60 credit card bill or fret because my car broke down or my daughter broke her arm. As a once famous person in a distantly fading movie once said, "it doesn't take much to see that the problems of three little people [or 100 billion] don't amount to a hill of beans in this crazy world."
Maybe it's impossible to truly internalize, but the next time life seems crazy or overwhelming, try to remember that you and yours, and everyone you know ultimately don't matter.