Someone sent me a file of photos of Costa Rican beaches and surf and beautiful languid people in shorts and sandals — sent it to me — here — on the frozen tundra where this morning my sandy-haired gap-toothed daughter and I struggled through the sleet and snow toward school, like Washington crossing the Delaware or Little Eva on the ice floes.

We can't all go to Costa Rica. Some of us must stay at our posts and sacrifice personal comfort to make sure the roads are plowed so the children can attend school and learn about gerunds and string theory and the lifeways of the Yoruba people. And so the National Guard can defend the border against the rapacious Canadians.

My daughter is in the third grade and she is full of questions such as when do we get there, who will she sit next to, and what will be served for lunch. She is a joyful child, even on a cold March day when the grown-ups are sunk in sepulchral gloom. She is plainly thrilled to be alive. And this morning she was happy about her assignment, a little diorama/shadowbox illustrating a scene from a favorite book, which she completed all by herself.

It was a shoebox that contained trees cut out of green paper and small plastic animals such as you'd buy in a dime store back when there were dime stores, and we walked, heads bent, through the driving snow, to deliver this treasure to school. And when we arrived, there on a long table sat the completed dioramas of other children.

I could see that many, many mother-hours had gone into the other children's projects, and some were of a quality that suggested professional help had been hired. I don't like to think ill of other parents, but it was perfectly clear that several of those child-submitted dioramas were done by teams of $200-per-hour designers in striped shirts and Gucci moccasins bent over a light table, saying things like, "I just think we need to ramp up that shade of green so we totally experience those trees" and "I don't like the way Laura and Pa interface with the house. And does the house need to be this little?"

My child's diorama illustrated (with green cutout trees, plastic animals, Scotch-brand tape) a scene in which a dog named Binky befriends a family of groundhogs, but some children's dioramas were illustrating scenes from "The Iliad" and James Joyce's "Ulysses." Why, people? Why? This naked ambition on behalf of one's children — it's so '90s, so California. Why overcompensate for your own frustrations in life by pouring time and money into your children's class project so they can gloat over my child's crude agglomeration of cheap green paper, 29-cent animals and three yards of adhesive tape?

I know that a man can't protect his child from unfair competition. When she grows up and takes the SATs and the LSATs and the LSMFTs, sitting in a long airless room with a No. 2 pencil and answering questions about the contrapositive logic of C being third if G is second, some other children will be receiving the answers from tiny diodes implanted in their earlobes. It's OK. We in the frozen north do not expect life to be fair. Yesterday a letter arrived misaddressed to me saying I will soon be eligible for Medicare, a cruel joke indeed, and now my child is exposed to cutthroat competition in the third grade. But we are hardy people.

My grandfather, James Keillor, could have headed for Costa Rica in 1881, but he came to the windswept prairie and joined his family here, who needed him. I could make a diorama of him, a plastic grandpa on a papier-mache hill with 20 plastic cows, and cotton balls to represent snow. And a paper thought-balloon glued to his forehead that says, "God's will."

That's good enough. I'm not out to dazzle you with my dioramic ability, and I would never hire professionals to do my child's schoolwork. Maybe your child will get into Princeton and my daughter will go to Brenda's College of Cosmetology, but the truth always catches up with you in the end. Children whose parents did their dioramas wind up rich and tortured by self-doubt and bounce in and out of rehab and probably will do some jail time. It's just common sense.

We can't live their lives for them, so let kids be kids, and let's you and I be on the watch for Canadians.

Garrison Keillor's "A Prairie Home Companion" airs from 6 to 8 p.m. Saturday on radio station KHPR 88.1 and from 6 to 8 p.m. Sunday on KIPO 89.3 His column appears Wednesday at www.honoluluadvertiser.com/opinion and in Sunday's Focus section.