Yes you can develop an allergy to anything at any time in your life,i also am allergic to cats, however my story differs in that i had not had cats in my life for over 15 years, and then along came Ash, anyhow to cut a long story short i am now owned by four beautiful cats, the ones in my siggy below, and by putting myself in amongst it all, the fur and dander, i have actually desensitised myself to a degree, i still have some problems, but mainly if i pat them then touch my eyes, other than that i manage extremely well, with the odd allergy pill and eye drops, but yes life with cats is very possible for me now ,more so than before, take all the advice given and enjoy those furbabies.