The perfume / cologne thing - I'm not like, super sensitive but there's a couple of brands out there that make me feel like my lungs are gonna collapse if I keep breathing them. Just some kind of chemical in there or something. It's literally physically distressing, especially if I'm already feeling headachy or a bit tired.
And sometimes it's not that, it's just the smell is so thick I can taste it from feet away. I just don't want my mouth tasting like whatever it is they're wearing.