It wasn't always bad, though. I was just telling my fiance last night about when Lyndsey and I shared a bedroom in Key West. We had matching pink, flowered comforters, and our twin beds were in an "L" shape, with the foot of her bed connecting to the head of my bed. This was before Lyndsey had her tonsils and adnoids removed, and she snored extremely loudly. I remember making a stockpile of beanie babies on the foot of her bed every night so that I could chuck them at her when she got going really bad. It was the most convenient way to shut her up, since I didn't have to get out of bed.
And when we were even younger, and we lived in Hawaii, some of our favorite games were "photo studio" and "school." I was the teacher or the photographer, and Lyndsey (and sometimes our brother, Jared, who was just a baby at the time) would be my eager students or subjects.
As we started to get older, we had the same taste in music and books. We found more things to talk about and do together. When either one of us would have sleepovers with friends, we would all hang out together. I took her to her first concert (where she almost died, just ask her). This was also the time when there was the most fighting. Hormones, I think. Too must estrogen for one basement.