The next time you find yourself anxious or distressed about a business or personal situation, you’ll find it to be enormously helpful to think about a reality of life that seems to escape people who are constantly stressed: things change!

This reality began to hit home with me in the late seventies, following a meeting with about a half-dozen of the top brass at Harper & Row Publishers (forerunner of today’s Harper Collins). Harper was a mainstream, 150-year-old company at the time, and neck and neck with other publishing giants such as Simon & Schuster and Random House.

My soon-to-be wife happened to have been with me at that meeting, a meeting that turned out to be a bit contentious. A couple of the big shots in the company were being especially uncooperative with my proposal for a long-term relationship that involved my publishing other authors’ books, though the tone of the dialog was civil.

After about an hour, my wife and I said our goodbyes and departed. At lunch, we discussed what had transpired at the meeting, and she made a comment that has proven to be remarkably insightful. “You know,” she said, “as I looked around the table, I thought to myself, ‘For all we know, most of these people won’t even be with Harper & Row a year from now.’“

I didn’t think much about her comment at the time, but within a few weeks my wife began to look like a prophet. The president of one of Harper’s top divisions, who had been at the meeting, left the company, and the vice president who had given me the most grief at the meeting was fired.

Within a few months, two more executives who had been in attendance bit the dust, so only two were left standing. Thankfully, with a large dose of persistence, I was able to get one of the remaining two to support my plan. (The other, who was his superior, ended up retiring shortly after we launched our project.)

As result of all this change, I was fortunate enough to be in a position to make publishing history with Harper & Row. With the company’s backing, I republished a book that had sold only about 10,000 copies before running out of steam. Through a full-page national ad campaign funded by Harper, I was able to market the book to No. 1 on The New York Times bestseller list, where it remained for fifteen consecutive weeks.

When the smoke had cleared, that once-dead book — Crisis Investing — had become the top-selling non-fiction book of 1980. And through my relationship with Harper & Row, I was able to publish a number of other New York Times bestsellers over the next couple of years.

It goes without saying that all this astonished the mainstream book-publishing industry. More important, it indelibly fixed in my mind the philosophy that you have to keep pressing forward when you believe in what you’re doing, because the landscape changes every day. If you’re patient, you’ll find that many of the obstacles that seem so insurmountable have a tendency to simply melt away or disappear with the passage of time.

If you are now stressed over some business or personal problem, benefit from my personal experience by keeping in mind that what you see in front of you at this particular point in time is only a snapshot of today’s circumstances — and that those circumstances are not static.

People get fired … they change jobs … they die … friends become enemies … enemies become friends … rivals go out of business … irritating humanoids move away … teachers and coaches retire … nuts fly airplanes into tall buildings and change a thousand and one things about day-to-day life, even creating new opportunities for alert entrepreneurs … the Internet is invented … Amazons, Googles, and Facebooks appear out of nowhere. The list is endless.

Since that historic meeting at Harper & Row, I can’t count the number of times I have witnessed this phenomenon in both my business and personal life. As a result, whenever I’m feeling stressed over a situation, I make it a point to take a deep breath, relax, and remind myself that circumstances will change. Change (which includes death) is the one thing about life that is certain.

The certainty that tomorrow will be different than today is what motivates me to keep moving forward. And the nice thing is that in the vast majority of cases, tomorrow’s circumstances turn out to be much better than they might have been had I not kept moving forward when things looked bleak.