I like Thanksgiving for precisely the reason retailers ignore it: There are no gifts and no decorations but an heirloom embroidered tablecloth, an ugly tureen with a crack in it and maybe a weird paper-and-cardboard turkey.

But what do we really know about the Thanksgiving feast? I don't mean the Pilgrims-and-Indians historical stuff. I mean the really important stuff, the stuff about the food.

Whenever I want to learn the truth, I go to the Urban Legends Reference Pages at www.snopes.com. They are the "MythBusters" of the Internet. And I found a cornucopia (Latin for "horn of creamed corn") of fun facts and fishy fiction.

For example: Turkey doesn't really make you drowsy. Amateur chemists have been saying for years, in their tedious know-it-all way, that turkey is full of tryptophan, a natural sedative.

And it is.

But -- and here is an important theme I may eventually score for violin and kazoo -- there isn't enough of the chemical to do anything in even the absurd portion you will greedily consume next Thursday.

The reason you doze off on the sofa in front of the TV after Thanksgiving dinner is that football is intrinsically boring and pointless. No, wait -- that's the reason I doze off. The reason you doze off is that you are full of carbs and, possibly, wine. All the blood has rushed to your gut to help convert gravy into love handles, and there isn't enough left to run your brain.

Not that there's anything wrong with that.

Among the things we feel less guilty about gobbling in large quantities are carrots and celery, also the last things left on the hors d'oeuvre tray (unless there is cauliflower).

Carrots, we lecture the children, are good for your eyesight, even if their other health benefits have been glazed over with brown sugar until they have the calorie count of a Mars bar.

Unless you have night blindness, carrots don't have enough vitamin A to affect your vision. Beta-carotene may reduce the risk of cataracts and macular degeneration, but you'd have to eat carrots like Bugs Bunny -- and then you risk turning your skin yellow or orange. He may not wear glasses, but what color do you think he is under that fur?

The cool part about the carrots-vision canard is its origin: It started as military disinformation. During World War II, the British air ministry put the word out that RAF pilots were able to shoot down lots of Nazi bombers on night raids because they were eating their carrots like good boys. Actually, they had a secret new radar system. Much more effective, though not as good with peas.

Everybody's favorite fun fact about celery is true, however: It is indeed a punishment for hitting the bar before the hors d'oeuvres spread.

It also has "negative calories."

Each 8-inch stalk has about 6 calories which you more than burn off when you eat it. Not because it takes more energy to chew it and pick the strings from your teeth, but because it is essentially indigestible. Your body burns a lot of fuel trying in vain to break it down into something useful. This is a good trick to play on your body, right up until it retaliates by giving your immune system the day off the next time you eat something that, unbeknownst to you, fell briefly into a hamster cage in your host's kitchen.

Which brings me to my next bit of bad news: There is no 5-second (or 3-second or 10-second) rule. Things that fall on the floor get bacteria on them, and it happens faster than you can bend over, especially if you are over 50.

This was proved in 2003, according to Snopes.com, by a high school student who conducted scientific tests involving Gummi Bears, cookies and ceramic tiles with E. coli on them. (Let's not go there.)

Not even the wholesome graham cracker, the stuff of many a fine pie crust, is reliably safe after falling on the floor. But it was originally designed to function more or less as saltpeter. The Rev. Sylvester Graham, a 19th-century Presbyterian minister and health nut, thought lust was dangerous and meat caused lust, so people should eat lots of veggies and fiber and unsifted wheat flour and get their minds out of the gutter.

That may not sound odd, but he also thought ketchup and mustard caused insanity. It's a good thing he never lived to see a Happy Meal.

Still, be thankful for his tasty crackers and foresight about fiber. He was mostly right -- though, on Thanksgiving, despite that meaty turkey, lust is rarely a problem.