I could have saved the day for $3.73, but in the long run I think I saved more than that.

Last fall, my daughter got a fish. I thought Angie might be ready for a dose of responsibility, so we went to the pet shop, where she chose the perkiest blue betta in the store. She promised to feed him, and I promised to keep his tank clean.

When we got home, Angie made space for our new roommate atop a nightstand in her bedroom. She named him Biff, in honor of the goldfish from her favorite cartoon, and decorated his new digs with drawings of sharks and killer whales.

“I don’t want to scare him,” she said. “These sharks and orcas are friendly and they might remind him of home.”

The little guy seemed happy. He swam through plastic seaweed by day and bedded down in the pebbles at the bottom of his tank at night.

After a few months, though, Angie lost interest in Biff. She quit drawing pictures of him and forgot to feed him. Just as I had expected, her pet became one more thing for which I was responsible.

Until one day I changed his water too hastily, and found him an hour later floating in the folds of fake seaweed.

Angie was still in school, so I drove straight to the pet store.

“You have to help me,” I said to the shop owner. “I need another Biff and I need him fast.”

We found a copycat betta, though he wasn’t quite the same. His tail was shorter and he seemed grumpy, but for less than $4 he would have to do. I took him home, plopped him into the tank in Angie’s room and waited for kindergarten to let out.

The new Biff was boring. He barely swam. He hardly ate. He had a habit of poking his head out of the water as though he had a death wish.

Angie, thankfully, never suspected a thing.

When the second Biff went belly up a few weeks later, my first instinct was to return to the pet store and spare my daughter the disappointment of a dead fish. I found a few dollars on my desk and started looking around for the car keys.

Then I stopped.

I didn’t want Angie to be sad, but if I kept buying new Biffs, what would I be setting her up for in the long run? Instead of facing disappointment, would we simply be postponing it?

Life inevitably brings disappointments — little ones, like a broken Silly Band or a twisted Slinky; and big ones, like a breakup or the death of a loved one. Facing the smaller ones now might help my daughter deal with the bigger ones later on.

Besides, I always figured that Angie had suffered the biggest letdown of all — her parents were divorced. Her father was no longer part of her daily life. What could be worse for a kid than that?

Over the years, I have tried to make it up to Angie. I have given her dessert even though she hadn’t eaten her vegetables and taken her to the playground even though she hadn’t behaved, thinking those actions could somehow compensate for the pain of missing a parent.

Then I realized that what I was compensating for was never really there. Angie missed her dad, but she was only 2 years old when her father and I split up; she remembers almost nothing of the time when the three of us lived as a family. Disappointment has not been her enduring emotion since the divorce.

It has been mine.

The man I married let me down. Life was not going to turn out as planned, and the person I was trying to pacify for that was not my daughter. It was me.

Replacing Biff would simply be another attempt at deflecting disappointment.

I put the $4 back on my desk. I set down the car keys. Once again, I waited for kindergarten to let out.

That evening, as Angie and I were settling into bed, I told her the truth.

“Honey, I have to tell you something,” I said. “Biff died today.

She sprung from the covers.

“What? He died?”

“Yes,” I said. “I’m sorry.”

She looked over at the empty space on her nightstand, at the drawings of sharks and killer whales.

Too often, we think our children feel exactly as we feel. We project our emotions onto them and then try to save them from our own hurt, shame or disappointment.

Maybe we don’t need to do that.

“Biff was a good fish,” she said, “but I think my next pet should be a shark.”

Wendy Fontaine’s “Party of Two” column appears every other week. Her email address is: [email protected] or follow Party of Two on Facebook.