Take Your Aspirin
Here's the secret they don't tell you about space travel: It hurts. Spacesickness is common, particularly for first-timers and anybody who launches into a bunch of fancy spins or soaring across the station before they've had time to get acclimatized. And trust us, hurling in zero-G is no fun. Worse, the effects of weightlessness can really do a number on your body. One symptom is lower back pain, caused by your spine stretching as the fluid within it floats. You get taller, but you also get achier. Headaches are another major issue. Without gravity, it's harder for your heart to do its job. Blood pressure drops and your blood doesn't reach your feet as reliably. Instead, it flows to your head, turning your face puffy and red and giving you a headache, just as if you'd been hanging upside down on the monkeybars.
Hygiene is, shall we say, "difficult" in zero gravity. Baths are a laugh and showers non-existent—the water would just ball up and float away. Instead, each person on the International Space Station is rationed one pre-moistened wet towel, a couple of dry towels, and several wet-wipes each day. These invaluable supplies are used to give yourself what basically amounts to a sponge bath. As for hair, well, there's a reason most astronauts keep their locks short. Space shampoo is dry and rinsing it out of your hair means carefully gathering a ball of floating water around your head inside a plastic bag.
Drink Your Friend's Sweat
Water is a precious commodity on the International Space Station and every drop is recycled via the Station's water conduction unit. And when we say every drop, we mean "every" drop. When astronauts are done exercising each day, they leave their damp towels to float around the station, where the sweat can evaporate, be collected by the conduction unit, and turned into drinking water.
Learn A New Language
With missions stretching as long as six months at a time, astronauts on the International Space Station learn a lot about each other, including how to speak in their partners' native language. In fact, most veteran American astronauts can speak Russian and most veteran cosmonauts can speak English.
Don't Ask, Don't Tell
That's the official NASA stance on whether anyone's ever had sex in space. We may never know for certain whether astronauts and/or their international peers are hooking it up up there, but we do know that, if they were, it would come with some less-than-sexy challenges. For one thing, there's no natural convection in zero gravity, so any heat you work up stays with you. At the same time, however, you also tend to sweat more in zero G, making outer space sex both hotter and wetter than that on Earth—and not in a good way. Another problem is that, in zero G, you naturally push away from anything you touch. That means anybody wanting to have sex in space would probably need to be strapped down and strapped together. Oh, and that drop in blood pressure we already mentioned? That would have dire effects on male "egos" galaxy wide.
Enjoy a Drink, If You Are Russian
Alcohol—in small, non-mission-threatening quantities—was always welcome in the old Soviet space station Mir (natch). But, when the Ruskies joined the crew of the International Space Station they found that American prudery reigned supreme over the heavens. From it's opening in 2000, the ISS was, officially, dry. This sort of thing was not acceptable to the cosmonauts and in January of 2006, they managed to talk Russian mission control into changing their rules. Good cognac—to be drunk by the thimbleful, as alcohol packs a bigger wallop in zero-G—returned to Russian supply kits, to, we presume, great fanfare. Americans, however, had no such luck. Officially, they're supposed to just watch in jealous sobriety when their Russian pals break out the drink.