Most people can build up a tolerance. I grew up with cats close to home and never noticed any allergy as a kid. When I got my own indoor cat though, I noticed itching and then flu-like symptoms that got progressively worse. Allergy medication completely relieved all symptoms, and rather than get rid of fluffy I took allergy meds daily for about 2 weeks, then every second ord third day for another month. Now I'm pretty much free of symptoms, but I occasionally pop a pill if the roof my mouth or hands start to itch for any reason.