AS THE SUMMER season ends and we head back to a normal routine, I’d like to share an essay passed along to me about 10 years ago by a colleague. The essay is titled “Four Lessons About How We Treat People.” I don’t know the original author.

Maybe one or more of these lessons will inspire. In the next few months, maybe something will happen in your world that will remind you of one of these lessons and you’ll know what to do.

First important lesson: Cleaning lady — During my second month of college, our professor gave us a pop quiz. I was a conscientious student and had breezed through the questions until I read the last one.

“What is the first name of the woman who cleans the school?” Surely this was some kind of joke. I had seen the cleaning woman several times. She was tall, dark-haired and in her 50s, but how would I know her name?

I handed in my paper, leaving the last question blank. Just before class ended, one student asked if the last question would count toward our quiz grade.

“Absolutely,” said the professor. “In your careers, you will meet people. All are significant. They deserve your attention and care, even if all you do is smile and say hello.”

I’ve never forgotten that lesson. I also learned her name was Dorothy.

Second important lesson: Pickup in the rain — One night, at 11:30 p.m., an older African-American woman was standing on the side of an Alabama highway trying to endure a lashing rainstorm. Her car had broken down and she desperately needed a ride.

Soaking wet, she decided to flag down the next car. A young white man stopped to help her, generally unheard of in those conflict-filled 1960s. The man took her to safety, helped her get assistance and put her into a taxi cab.

She seemed to be in a big hurry, but wrote down his address and thanked him. Seven days went by and a knock came on the man’s door. To his surprise, a giant console color TV was delivered to his home. A special note was attached.

It read “Thank you so much for assisting me on the highway the other night. The rain drenched not only my clothes, but also my spirits. Then, you came along.

“Because of you, I was able to make it to my dying husband’s bedside just before he passed away. God bless you for helping me and unselfishly serving others. Sincerely, Mrs. Nat King Cole.”

Third important lesson: Always remember those who serve — In the days when an ice cream sundae cost much less, a 10-year-old boy entered a hotel coffee shop and sat at a table. A waitress put a glass of water in front of him.

“How much is an ice cream sundae?” he asked.

“Fifty cents,” replied the waitress. The little boy pulled his hand out of his pocket and studied the coins in it.

“How much is a plain dish of ice cream?” he inquired. By now, more people were waiting for a table and the waitress was growing impatient.

“Thirty-five cents,” she brusquely replied.

The little boy again counted his coins. “I’ll have the plain ice cream,” he said. The waitress brought the ice cream, put the bill on the table and walked away. The boy finished the ice cream, paid the cashier and left.

When the waitress came back, she began to cry as she wiped down the table. There, placed neatly beside the empty dish were two nickels and five pennies. He couldn’t afford the sundae and still leave a tip.

Fourth important lesson: Giving when it counts — Years ago, when I worked as a volunteer at a hospital, I got to know a little girl named Liz who was suffering from a rare and serious disease.

Her only chance of recovery appeared to be a blood transfusion from her 5-year-old brother who had miraculously survived the same disease and had developed the antibodies needed to combat the illness.

The doctor explained the situation to her little brother and asked the little boy if he would be willing to give his miracle blood to his sister. I saw him hesitate for only a moment before taking a deep breath and saying “Yes, I’ll do it if it will save her.”

As the transfusion progressed, he lay next to her and smiled, as we all did, seeing the color returning to her cheeks. Then, his face grew pale and his smile faded.

He looked up at the doctor and asked in a trembling voice “Will I die right away?”

Musician John Legend said “The key to success, the key to happiness is opening your heart to love. Spending your time doing things you love and with people you love.

“Years from now, when you look back on your time here on earth, your life and happiness will be way more defined by the quality of your relationships, not the quantity.

“You’ll get much more joy out of depth, not breadth. It’s about finding and keeping the best relationships possible with the people around you.”