Those charts! All my life the charts have said I, at 5'6," should weigh around 130 and I know I'm best at about 110.
I once worked with a bunch of women and we were always calling ourselves fat. Since I was the smallest they would moan and roll their eyes when I said I needed to lose a few pounds.
One of us was married to the PE teacher at Wright State University so he agreed to weigh us all underwater for the ultimate body fat/weight decider. Turns out my friend who was my height weighing 145 was just right and I, at 110, was the "fattest" one of us all. He said I should weigh 102.
This, also, explains why I can only eat 900 calories a day if I want to lose 1 pound per week.