I get irrationally happy when I hear certain sounds. One of them comes at midnight, when I'm working late. It's the sound of a street sweeper, coming up the street. I assume you know what a street sweeper is. It's a truck, usually white, with big brushes sticking out from the side of the truck, that are spinning, whirling, parallel to the ground, kicking up, then sucking up, the debris and waste that has accumulated in the street, near or at the curb. 
Copyright © by Ponchitos, at en.wikipedia
It makes a very distinctive sound, audible while the sweeper is still a good ways off, as it moves up the street slowly toward you. It's a deep hum from the sweeper's engine, married to the soft swish of the spinning brushes, up against the curb. As it gets louder, and nearer, I always run to the window to see. And, sure enough, along comes this hulking white thing, with its high beams piercing the midnight darkness. It looks like some mechanized beast. Never was I so happy to hear any other beast.
Why? Well, I've heard that sound since I was a little kid. It was a far, far, simpler world, then. But over the years, my childhood landscape has changed, seven times over, and there are new technologies for everything, all with their peculiar new sounds; but in the midst of them all comes the old familiar sound of the street sweeper, at midnight. I've heard that sound for most of the time that I have been on earth. I've heard it for decades. It enchants me that these machines are still rumbling around, in my world.
For, things keep changin', as Bob Dylan observed. Like: the times we live in, our ways of doing things, our locks, our home, our transportation, shopping centers, cinema complexes, commerce, technologies, the way we dress, our music, our body, our strength, and all the sights and sounds around us. Change, change, change. "You'll have to get used to it. That doesn't work that way, any more. Sorry. Things have changed."
Nostalgia is in full season. Once considered a disease [1770, "debilitating homesickness" from nostos (homecoming) and -algia (pain, grief)], the word "nostalgia" graduated around 1920 to a disease-less meaning: "a wistful desire to return in thought or in fact to a former time in one's life; a sentimental yearning for the happiness of a former place or time", and in our time it has mutated again to the simple " feeling of appreciation for the past or things related to the past." In other words, "before all these changes." That's nostalgia. You saw it in the recent elections, you see it in the continuing strength of the Tea Party movement.
Nostalgia is in season because, as I said, life lately seems like nothing but changes. Researchers Holmes and Rahe even made a list of life's changes, and assigned a certain stress level to each. You can find (and take) the test at http://tinyurl.com/384l43. What you notice, when you study that list, is that the degree of stress is directly related to the degree of change each event represents in your life. The greater the change, the greater the stress. And there are lots of changes in many people's lives. So therefore, lots of stress.
So, how do we get rid of so much stress? How do we cope with so many changes?
Archimedes had the answer: "Give me a place to stand, and I will move the earth." The place to stand must, of course, be immovable. Likewise with the fulcrum, and the very long pole. But his metaphor was important. Find a constant, a firm place to stand, and you can then turn to deal with change. In our lives, a Constant is anything that does not change; anything or any person that remains unchanging, invariable, steadfast, faithful, and dependable.
The key to coping with stress is not found by ticking off, listing, noticing, remembering and meditating upon, all the changes we are having to deal with, in our life.
It is found by listing, noticing, remembering and meditating upon what in our life has remained constant. Life is composed of both Constancies, and Changes. We live at our own peril if we only notice the Changes. That can drive you nuts. We need to notice the Constants in our life more than we do; for from them, we derive our strength to deal with whatever Changes we may face.
The Constancies I have noticed most, are: character ( as hopefully we stay essentially the person we are, all our lives), true friends, classical music, love and trust, our skills, talents, and gifts, faith, and (for those who believe) the eternal God.
You can make up your own list. And you should. Ask yourself, what has remained constant throughout your life, to date?
I'll leave you now, with these thoughts. So, cue the music, cue the old familiar sound of street sweepers at midnight.
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For a history of street sweepers, see: http://en.wikipedia.org/wiki/Street_sweeper For street sweeping in my town, see: http://tinyurl.com/29xf8gg If you're curious about the town overall, see http://en.wikipedia.org/wiki/Danville,_California