Wow that is interesting. Never noticed. I have one friend down here who perpetually has bad breath. It's horrid since I have had to sit next to her for an entire semester. She is not the type who would think to use perfume either though. Most of my friends who do like perfume at all, even the tiniest bit, are good w/their oral care though. The other kind of bad breath doesn't so much bother me (garlic/onion) since its basically from what they ate rather than poor personal hygiene.