
It is so true . . . I've bought a lot of clothes recently so most of my pants are 8's and 10's now. But here is a story from a while ago when I was going from 12 to 10. I was at Kohl's, and I took three pairs of pants into the dressing room. One was a size 12 from one brand (CK I think), the others were sizes 10 and 12 from another brand. Guess what, the 10 from one brand fit, and the 12 from the other brand was so small I couldn't zip it up!!
Another one -- I was at Express since they were having a jeans sale, and I grabbed this one style in a 10 regular. It fit but was too long, so I grabbed the short. The short was tighter!! Since when do pants lengths dictate waist size? The girl at the store then told me that not only do they sometimes make the short ones smaller all over, but that they have their jeans manufactured at three different places, and the ones from all three are different! So you could take three pairs of size 10 short jeans in the same style and they would all fit differently!
Anyway, today I am wearing size 10 jeans that are a little loose, and a size small shirt. The funniest thing is that even though I am wearing a size small shirt, I am wearing a british size 32FF bra! How often do FF breasts fit in a size small? Most of my shirts nowadays are mediums, but I still have an X-large button-down that fits pretty well. I also have two suits, both size 12, which are only a little big. I also have a size L dress that is still too small!!
One trick: clothing you buy in stores that cater to teenagers is always cut smaller. A large from Charlotte Russe is waaaaay smaller than a large from a department store! And I fit into size 8 jeans at Old Navy months ago but I still buy 10's from other stores, so that one is kind of reversed!