Bra sizes

I’m currently a 32C and I was just trying on my bras when I found my old 32A bras. I tried them on and how the hell do some of them still fit as in cup size? I’ve been measured my many people and they all have said I’m a C cup but I don’t get how my A cup bra still fits? I’ve asked my friends this question and they said it could be the padding in the C’s that make it fit but I’ve tried on C cup bralettes and bras without padding and they still fit.