one size fits all

I've never bought into the idea that a clothing item could be "one size fits all".  But this skirt has magically fit me no matter my weight.  I originally bought this skirt 50 pounds heavier, and yet it still fits. 

In the past I have always worn it with a turtleneck sweater (either black or turquise) so I'm really living on the wild side pairing it with a cardigan.