I keep a small fish tank in my office, which can be a conversation piece for students and staff who come to chat.

But the lamp burned out so I stopped off at the Woodstock pet store yesterday to buy a replacement. Fortunately my neighborhood keeps me away from The Mall with a few small stores where I can buy fish food, light bulbs, flowers, coffee and stationery.

Woodstock is a working class community with pockets of Russian immigrants, two espresso bars, Otto’s sausage shop, Lady of Sorrows Catholic Church, Laughing Planet restaurant and Reed College.

When I stood at the counter to pay for the $2.99 aquarium lamp I reached into my pocket book and found a dollar bill and 31 cents. I told the woman I didn’t have enough change, although I offered my debit card.

She waved me away. Just bring it when you can, she said. You’re in here all the time. I know you.

What was weird is that I always bring my dog with me to the store. Everyone remembers Romeo. No one remembers me. So I was touched and relieved, and promised to return with two dollars and ninety-nine cents.

On the way home I marveled at my sweet little community and the act of kindness. I wished my daughters were with me to share the memory.

And then I remembered something that happened when I was a kid.

I was in the car and my mother was driving. I was about 8 and was home from school, and we were on our way to the market. (I stayed home as much as possible in the first four grades of school. Kids made fun of me because we were poor, my parents had divorced and I was skinny as a noodle.)

My mother stopped the car at the curb and gave me a handful of change. Take this to the cashier, the second one when you walk in, and tell her your mother said to give this to her, she instructed.

I was dumbstruck. What’s a cashier? Why does she need money? What if she gets mad at me? I looked at my mother and protested: I didn’t want to walk into the store by myself. Why couldn’t she go? But my mother was stern and she insisted. She said, tell the lady that your mother owes her this money.

So I took the change and walked into the store, waited for the lady at the register to notice me and then handed her the money, saying my mother said I was supposed to. At first she was confused. My mother said she owes you the money, I said.

The cashier laughed and said thanks. She sort of dismissed me because the amount of change I offered was small, less than a dollar. I ran back to the car. Once inside, my mother asked me what happened. I told her, and she seemed satisfied. She told me that she had bought groceries and was short some money and promised the cashier she would bring back the change.

I don’t think my mother considered this a teaching moment: I just happened to stay home from school that day. But it was etched in my memory. The teaching moment for me was that my mother kept her promise, even though the amount she owed was small—so small that the cashier just laughed. But it sure left an impression with me.