1) You have to love repetition! Think running laps around a track is boring? Telling a child not to climb on the furniture over and over is no picnic either. Or my personal favorite, "get your finger out of your nose!" (said while at a restaurant, a wedding, or any other equally embarrassing place).
2) You need pipes!

3) Patience like you've never had before! Those little bundles of joy will test you over and over again. You'll notice the "testing" around the time your baby has his or her first taste of cereal. After a few weeks the cereal will not be as exciting to the baby anymore and he'll chuck the bowl off his highchair. This will be amusing to him, especially if he gets a reaction from you, and this new skill will continue on until at least 18-months. Which brings me to my next quality.
4) The broom is mightier than yelling! You'll have to clean like you've never cleaned before (reread #1 about repetition for full effect). Breakfast - baby throws food on floor, chucks bowl, spoon etc., takes off bib and messes up clothes, rubs hands full of cereal all over her head (and creates the "Something About Mary" look), discovers spewing is more fun than swallowing etc. Lunch - more of same but now you've probably served foods that stain a bit more AND you've spent most of the morning getting the highchair, baby, utensils etc. cleaned up for lunch. Dinner - you've spent more time preparing the meal that will be thrown, mushed, squished and are a little less patient about the mess. You've also cleaned up the mess twice already. Snacks - in between meal messes (squishy banana is a favorite to clean up).
5) Spatial skills! If you don't drive a mini-van or large SUV, you'll need to figure out how to contract your stroller and fit it in the back of your car quickly. If you live in a cold or wet climate, you'll need to do this lightning fast. Good luck with that one. And forget about putting together baby toys, cribs, high chairs, strollers, installing car seats properly etc. Hire professionals for all those things. Avoid anything that says, "light assembly required", if you do not possess spatial and/or mechanical skills. I don't think there is a course to take for any of those skills but I could be wrong.
6) A bright and sunny disposition! We were thrilled when our little girl peed on the potty the first time around, and the second, and the third time. We threw a party. We were overjoyed. She's been potty-trained for almost two years now and she still expects a marching band every time she goes. It's hard to throw a party when she has to go in the middle of the night and wants mommy or daddy. Oh please let it be daddy tonight. Please. You get my drift.
Okay so that's all for now. If I haven't scared you enough to increase your birth control methods (try them all), you are one of those people that is brainwashed into thinking your child will be different. It's probably the hopeful grandma-to-be doing the brainwashing so there's nothing you can do about it. That is how the species continues on, I guess.