There are no accidents. And so it must be that the four-inch memory foam mattress topper sprawled across the floor of my garage is there for a reason.

The obvious one is that more than one guest, including grown children I’d like to see as often as possible, have commented that the guest bedroom mattress is a “character-building experience.”

But I think the real, deeper reason – timed just before the holidays – was to remind me of the perils of online shopping.

“Any kind of topper would be fine,” my daughter said. “Just one of those egg crate things would be an improvement.”

But a run to a local store proved that finding “one of those egg crate things” is not so simple. Some have crates deep enough to hold robin eggs. Some could hold ostrich eggs. Some have regular old foam. Some have memory foam reportedly developed by NASA. And all but the robin egg variety are pretty darned expensive.

“I’m sure,” I muttered, leaving the store, “that I can find something cheaper online.”

And voila! That is exactly what happened. For a fraction of the ostrich egg cost, I saw one that was four inches of solid memory foam. No holes at all! What a bargain! The only drawback – slight, I thought at the time – was that I could not see it, feel it, or ask questions about it, only picture it in pristine glory on an online bed. Quickly, I popped it in my cart and pressed “Submit.”

And so, when the very compact but weighty box of mattress topper arrived a few days later, with instructions to “air it out” for 48-72 hours to release any noxious fumes (noxious fumes?) and expand it to its full shape and size, I decided the perfect place was the garage. Who, after all, wants noxious fumes airing into a second-floor bedroom?

Me, as it turns out. Because when I’d snipped through a fortress of plastic wrap, a cross between the Incredible Hulk and the Pillsbury Dougboy emerged. The cream-colored puff inflated like those magical seahorses they sell in novelty shops. (“Just add water and we grow 1,000 times our original size.”) It is folly to save the box for possible return. I could no more stuff the topper back in it than put the proverbial toothpaste back in the tube.

My plan had been to toss it on top of one of the cars for a complete airing. It was, after all, only foam. But there was no tossing. I could barely lift up a corner to straighten it out. In the end, I had to back out a car to make room.

The only consolation is that when I called my son to rescue me, he was unfazed.

“Of course I can get it upstairs,” he said. “It’s only foam.”

Apparently, this rush to happy assumption is genetic. I don’t know if the laborious trek upstairs will cure him of online ordering.

But the only reminder I need to be more cautious is a new three-word Post-It sign by my computer. It says: “Sleep On It.”

Copyright 2012 Pat Snyder