Well, my first two cats, I didn't realize I was allergic, because there's so many other allergens anyway. It became pretty clear the cat was a significant allergen with the second one, but it would take a lot for me to want to rehome a cat who I had bonded with and was well behaved. The current one was supposed to be a barn cat, which would be fine, but at least lately he's decided to hang out indoors a lot (he's well behaved and a snuggler). Cats and I get along well, other than the allergies.
In summary, humans do all sorts of things that are not wise; of all the stupid things I could do, this isn't so bad.
I can breathe, breathing through my mouse is normal for me, so if allergies clog up my nose, it's just another day.