I remember when I first started... it was so COOL! I couldn't believe that no one else I knew (except the guy I was dating who talked me into trying TKD) knew about this cool stuff. I was so excited... although people looked at me funny when I bowed coming into work (the entrance to the lab was the same configuration as the entrance to the dojang... you know how that goes...). Over the 19 years I've been in TKD, some of the newness has worn off - but never the enjoyment and excitment. I love teaching, and I love practicing and learning new things.
Most of my friends have heard about it... seen me limping last year after my last testing - when the instructor's wife (who is a nurse practioner, in addition to being an I Dan, and knows whereof she speaks) tells you later she can't believe you kept going after what sounded like a ligament in your knee ripping... well... it was my IV Dan test - and I do have 5 years to heal now... but still... it is an addiction - but hey, at least it's a (mostly) healthy addiction!
I don't talk about it at work much, because I teach middle school, and if I talk about it where the kids can hear, they start asking things like "can you break this desk?" - to which the only reasonable answer is "do you have $100 to buy a new one?", followed by "look underneath, what do you see?" (answer) "A metal bar" (me) "no" - and anyway, desks are particle board covered with laminate! Not the best breaking material in the world. But all of my friends indulge me when I talk about my students (both TKD and school), so it's not that bad.
One of my friends even came to me once, somewhat embarrassed, because her then 9 year-old daughter's doctor had recommended martial arts as a way to teach the child discipline (slight impulse control problem), which I had already recommended; my friend, who had thought I was kidding, came to me to ask about finding her daughter a class, since I teach on the other side of town from where she lives (a 45 minute drive each way for a 90 minute class is a little impractical for a 9 year-old, after all!).
My father always accepted my TKD training, even if he's never truly understood it; my mother thought it was a phase I was going through until about 10 years ago, when she came to watch my class, and talked to the
parents of some of my students - after that, she understood the instructing part, but she's never understood the rest of it, and probably never will.