I finally understand my parents’ long-ago frustration with me and my sister when we left doors open.

We grew up in your standard ranch-style, single-level home. All the doors in the house functioned properly, with latches, doorknobs and the like.

But we still left them open.

In the summer, doors left ajar would let bugs into the house and disrupt my dad’s hard-won passive cooling by letting hot air in and cooler air out.

In the winter, open doors would let heated air from the house out into the cold, which in my kid’s brain I imagined as swirls of cartoon air wildly fleeing the house every time a door was left open. You’d think that having the responsibility of fetching the firewood would have made my sister and me a little more aware of things like open doors and escaping cartoon air, but based on the number of times my dad bellowed “SHUT THE DOOR!” during my childhood, I’m guessing it didn’t.

Fast-forward to the present. I have inherited my parents’ disdain for leaving doors open, and my children (and my husband, to some extent) appear incapable of closing a door.

I cut my husband a little slack because he grew up in Southern California, where leaving the door open will never make the furnace work overtime and, in fact, is the only source of cooling in many homes.

But our kids are another story. Since they were old enough to turn a doorknob, they’ve been educated on the importance of energy conservation and the role of a well-sealed exterior door in keeping a warm house warm and a cool house cool, not to mention keeping our pets where they belong. So I thought.

Nonetheless, I often find myself bellowing “SHUT THE DOOR!” in a tone my dad would be proud of. Last weekend, for example, the open-door debacle unfolded thusly:

One child is instructed to feed the dog. First he retrieves the food scoop from the back deck, leaving one sliding glass door open in the process. Then he leaves the door to the garage open when he gets the dog food. Finally, he goes out the second sliding glass door to give the dog her food, leaving that door wide open.

“SHUT THE DOOR!” I yell, which results in one door being closed.

The palpable draft of chilly air flowing through the house lets me know the doors aren’t all closed. “SHUT THE DOOR!” I yell again.

Still not all the doors are shut. And now the dog is in the garage eating spilled dog food from the floor.

“SHUT THE DOOR!”

Finally the dog is back in the house, the doors are all shut and the furnace is cranking out the heat, just in time for a neighbor kid to come over to ask the boys to play. Off they go out the front door, leaving it only slightly ajar, but wide enough for the cat to weasel his paw in the crack and open it wide enough for the dog to get her maw in the opening and throw it open all the way.

Now the door is wide open, the cat is playing chicken with a car in the street, and the dog has run to the neighbor’s to catch up with a handsome husky who lives there.

“SHUT THE DOOR! GET THE DOG! CATCH THE CAT!” I yell.

Meanwhile, the furnace is cranking away.

The neighbor kid helps my boys get the dog fenced in. The cat’s hiding under a bush somewhere — I give up on him. The door gets shut, the dog gets put in the backyard and the house is now 5 degrees colder than it was earlier.

The furnace whirs on.

Next I notice the dog in the front yard. The boys didn’t latch the gate.

“GET THE DOG!” I yell.

They get the dog, put her in the house and run off to play with the neighbor kid without bothering (of course) to check if the door closed all the way.

It didn’t.

I close the door and toy briefly with the notion of locking it.