kittens... you forget just how very annoying they are until you have one again. my goodness. let me tell you some annoying things about kittens.
a kitten doesn't necessarily like to sleep at night. sometimes they just want to play. even when you have to wake up at 6:30 am. a kitten does not care.
a kitten can cram into some pretty small, ridiculous places. this can lead to a general panic. this can also lead to a kitten nearly being killed when it decides to crawl behind the mattress just before you push the mattress against the wall (true story, happened last night - he's fine, though, don't worry).
a kitten likes to bite and claw everything. your clothes, your furniture, your books, your limbs. kittens do not care if you are allergic and will develop terrible welts and hives.
a kitten doesn't have any concept of personal boundaries. he will put his paws in your eyes, he will climb your pants, he will crawl under you when you are sleeping and become extremely offended if you roll over on him. he will also feel free to clean himself while sitting on the keyboard of your laptop.
a kitten will possibly throw your other cats into fits. don't be surprised to find yourself awakened in the middle of the night as all three felines vocalize at each other.
a kitten will pee on the floor (and on your sister). he will then track little urine footprints all over the house until you catch him and wipe him off. this is particularly charming.
the problem with all these points is that you don't seem to remember them when your kitten grows up into a (decently) well-behaved cat. also, kittens are so adorable as to make up for all these terrible faults. when they curl up on your lap and fall asleep purring, you realize that a little kitten punch in the eye is not the worst thing that can happen.