If it's your ideal weight (as in, you set it yourself as a realistic goal and you weren't told over and over again that it's perfect) and you're HEALTHY at that point, and you're not like srsly-omg-have-to-starve yourself just to stay size 3, that's not really a big deal. It's not the number that's important - it's the reasons.

But touting size 6 as "perfect" isn't the way we want to go in educating young girls about their bodies. There're some girls out there who're naturally healthy and in proportion at size 8, and they should be left alone. Similarly, there're some girls out there who're size 0, and they're accused of being anorexic... they have problems with self-esteem too as a result!