you can tell people all you want. you've actually had a similar reaction to what i got when i tell people. from stories i've heard, we should consider ourselves lucky.
my belief in these stories is pretty limited however. i've yet to ever meet a person who particularly cares about me being a furry, let alone someone who even knew what it was before-hand. people really have to stop thinking that furry is like homosexuality in any way. it's not. homosexuality is a sexuality... furry is a sub-sub-sub culture (probably not even that). pretty much no one will know what it is unless they're involved in some way, so the best way to tell people about it is to let them know that you have some kind of interest in animals, and cartoon animals... or animal drawings or whatever your chosen outlet is. if they get curious, tell them stuff! chances are they probably think you're a little bit quirky already (not in any kind of sexual way) so it's no big deal.