Hmmmmm, daffy. You can get away without wearing a bra every now and then..you lucky lady!
Mind you I did read somewhere that small ones drooped more in later life as a flatter chested woman is more likely not to wear a bra than a woman with boulders ;o)
Ive seen some naked old ladies when I was a teenager ( I used to work in a nursing home outside of college, just in case you are wondering why I had that misfortune) and even the flattest chested old ladies had the sock with stones in boobs. Incline bench presses re the only way to save your breasts.
If women don't wear a bra then , in years to come they will be that droopy thay they will be able to tuck them into their trousers , or sew press studs onto the nippies and use them as braces. !!!