Whether it’s been absorbed over expense-account dinners or passed down through generations like a werewolf gene, much of what you think you know about wine is probably incorrect. Not all Rieslings are sweet. Screw caps are no longer the mark of the undrinkable. And here is a little breaking news for anyone who’s been snubbing Merlot since Sideways: The superlative 1961 Cheval Blanc that Miles finally uncorks at the end of the movie (after extolling the complexity of Pinot Noir for two hours) is, in fact, a Merlot. So swallow your pride, forget everything you’ve been told, and start here.

Contrary to what you’ve heard, most wines do not get better with age. Modern winemakers generally intend their products to be polished off within a few years. If you’re faced with two vintages of the same wine at the store, go for the younger one. Unless you’re in a shop that specializes in ancient stuff, the place may just stockpile cases in a back room, which doesn’t bode well for the long haul. A bottle kept at 70 degrees will age twice as fast as one stored at cellar temperature, 55 degrees.

Wine-list values aren’t where you think—cheaper wines actually get the highest markups by percentage. A $45 Muscatel probably cost the owners 15 bucks, but they’re banking only a couple hundred off the $3,000 Pauillac. On the other hand, don’t think the least expensive options are meant to appease the fixed-income set. At finer restaurants, says Jean Luc Le Dû, owner of Le Dû’s Wines in Manhattan, sommeliers actually put more thought into the bottles under $50, because “it’s much harder to separate the good stuff from the shit in that range.” The perception that wine stewards will look down on you unless you blow your entire allowance on blockbusters actually irritates them—they’re there to guide you.

When the waiter pours you a taste, don’t get all theatrical about it. Your job is simply to assess whether the wine is corked or oxidized. Corked wine has a moldy, wet-cardboard odor. And if it’s oxidized, it will smell almost like sherry—get yourself a cheap bottle so you can recognize the aroma. In either case, don’t feel bad about sending it back—usually the distributor (not the restaurant) eats the cost. After signing off on the bottle, most diners expect to see older vintages decanted, but think twice: Many are too fragile. “Some of them are amazing for 15 minutes, and then they just fall apart” with exposure to oxygen, Le Dû says. If you’re worried about sediment, just call your big wine in ahead of time and have the sommelier put the bottle upright, so it can settle. Le Dû suggests unleashing the decanter on younger wines instead—especially whites.

First and foremost: You are probably drinking your red wines too warm and your white wines too cold. A few sommeliers even think both should be served at around 60 degrees. Good restaurants pour reds at cooler than room temperature—which can infuriate the clueless. “One guest screamed at me that I should bring my cellar up to 68 degrees every day before service,” says Paul Roberts, wine director for Per Se in New York and the French Laundry in California. You shouldn’t banish your whites to the ice bucket, either. Chances are they’re already kept at 45 degrees for frost-loving Americans; just let them warm up on the table.