Some things should never make a comeback: the Yugo, Celebrity Boxing with Tonya Harding and Danny Bonaduce, the lime-green pantsuit Hillary Clinton wore on her first campaign swing through Iowa.
I put Spam on the no-comeback list, too.
Yet now comes word that Spam - the pink slab of pork and ham that comes in a can from Hormel, not the junk mail in your inbox - has become wildly popular again in this staggering economy.
At a little over two bucks a can, it's a cheap way to eat something that looks like meat's illegimate cousin, but is, in fact, actual meat.
What's really amazing, though, is that this isn't really a comeback for Spam at all. Because it never really went away.
In fact, since Jay Hormel invented it in 1937, almost 7 billion cans have been sold worldwide. In the U.S. alone, more than 90 million cans are sold every year.
Which means even though Spam has been the butt of jokes and Monty Python skits and a hit Broadway show (Spamalot), a lot of people still love the stuff, recession or no recession.
To find out why, I called Dan Armstrong and Dustin Black, a couple of 30-ish advertising guys in Minnesota who are so passionate about Spam that they wrote The Book of Spam, billed as "A Most Glorious and Definitive Compendium of the World's Favorite Canned Meat."
As you might have guessed, Armstrong and Black know more about Spam than is healthy.
They have toured the Hormel factory in Austin, Minn., and endured the penetrating odor from the nearby slaughterhouse, where thousands of Spam-worthy hogs are butchered.
They have visited Austin's Spam Museum, "a sparkling 16,500-square-foot monument" to the Spam lifestyle, Armstrong calls it, adding, "It's a lot cooler than I thought it would be."
And they can expound at length on the Spammobiles, trolleylike vehicles that travel around the country on goodwill tours, dispensing free samples of Spam to all who, um, actually want them.
Armstrong said he grew up eating and liking Spam, encouraged by a dad who called it "the meat that won the war."
That would be the Big One, World War II, when Spam fortified hundreds of thousands of American soldiers and sailors, who apparently viewed eating mushy meat out of a can as a minor inconvenience, preoccupied as they were with trying not to be killed by the Germans and Japanese.
"So Spam always had this patriotic aura to me," Armstrong says. "I felt I could conquer anything with that in me. It was sort of like Popeye with his spinach."
Black says he ate Spam only occasionally as a kid. But now he eats fried Spam sandwiches, Spam burgers with a slice of pineapple and Spam musubi (Spam, fresh seaweed, sticky rice and soy sauce).
Armstrong feels Spam has been hugely misunderstood, largely because of its color, a shade of pink more commonly found in certain types of exotic coral rather than meat.
People "say, 'Why is it pink?' " he said. "I say, 'Well, hot dogs and salami and bologna are pink. Meat is naturally gray and Spam has a little sodium nitrite in it to keep it pink.' "
Black feels Spam gets a bad rap because of the whole meat-in-a-can issue."
"I really feel people are afraid of shelf-stable meat," Black said. "And people are still scared of the gel. They talk about the gel all the time."
This would be the gelatinous goop that came atop Spam, ensuring that it would quiver like a mound of meat pudding when you plopped it on a plate.
But Black said the gelatin has been gone from Spam since 2001. That's when Hormel launched a secret initiative code-named Project Aurora - you can't make this up; it's in the book - that added potato starch and got rid of the gel.
Here's another astounding Spam factoid that Armstrong laid on me: It's big in Hawaii.
No, not just big. Huge.
"They serve it in every Burger King and McDonald's," he said. "You can get Spam McMuffins, Spam and eggs, everything. I don't think you can go to any food establishment in Hawaii and not find Spam."
You can debate whether this is good for tourism until the pigs come home.
But The Book of Spam also notes that those crazy Hawaiians hold an annual event called - we may be venturing into Spam Esoterica Hell here - Spam Jam on Waikiki Beach, during which 20,000 fans turn out to see top chefs show off their best Spam dishes.
In any event, Armstrong and Black say it's no surprise that Americans turn to Spam in these anxious times of buyouts, layoffs and whipsawed stock prices.
"I think psychologically it goes to a deeper core issue: It's comfort food," Black said. "People remember it from the '40s and '50s, and that was the golden era in their memories."
In Hawaii, apparently, it's still the golden era.
But let's not get into all that again.