According to Oprah and other media people about 70% of women are wearing the wrong bra size. Not only is wearing the wrong size uncomfortable its down right silly. Why would you want to wear something for 16hours a day that just doesn't fit. Not to mention that your boobs are incredibly sensitive and just simply feel more than the rest of your body.
I decided to look up the history of the bra using the ever reliable Wiki as my information source. What I found was too complicated to summarize, but if you are interested click on the wiki link. One thing I did find interesting is that both world wars effected the bra industry greatly, first because of metal and the second because of the woman's role in war.
I personally hate bra's and they are the first thing I remove when i walk in the door (the second is socks, I like my toes free). When I was in Florida I decided to go into Victoria's Secret and get fitted, the girl in the dressing room tried to convince me that I was a D cup. I tried on several D cup bras and just simply did not fill them (I could have told her that). I am a true 36C, which a home measurement confirmed today.
Here are some tips I found on the Internet about fitting.
From a web site called The Bra Guide I learned that if you are experiencing: Breast spillage, bra puckering, bra riding up, bra digging into shoulder and under wire poking you are wearing the wrong size. You also need to figure out what type of bra works best for you. I'm a huge fan of the cleave so i like a 3/4cup bra with some push up (if you got it flaunt it right?) .
This is Victoria Secrets "How to Measure"
Hope you find the right size for you...