Folks seem to fall into four (broad) categories. (ok it's more than four, but bear with me on this):
1) those who do yoga and are happy to talk about it
2) those that like the idea but sheepishly laugh and say "Well, I hear it's good for you but I can't even touch my toes/I'm not flexible/I have injuries."
3) those that maybe tried yoga, but now shrug their shoulders and say they can't because "It was too boring/it was too hard/it was too hot/it was too weird/I hate all that quiet time meditating/breathing."
4) those who roll their eyes and give you a crossed-arm down glance while telling you they "DON'T do yoga."
Let's acknowledge that Group #4 would be a hard sell, and frankly speaking if someone is dead set against even TRYING yoga, there's no point in trying to convince them (it's like politics).
Group 3, well, might not be ready, and are set on the idea that any kind of regimen is to be faced with a frown. They MIGHT be interested in taking a class if someone they really admire would go with them or tell them about a place they recommend. Still, I take no pleasure in trying to convince someone that yoga is wonderful. You either feel it or you don't; if the mind doesn't want to accept the idea, no amount of honest conversation is going to work (maybe some subliminal advertising or mass marketing on the level of soft drinks and pharmaceuticals, but that's getting ever so slightly away form the core values in the tradition).
Group 1 is a no-brainer. Group 2, now there is a group that I love to talk to. Today alone I had 10 people walk up to me at a health fair and say, verbatim, "I hear it's good for you but I'm not flexible." My response is one of two depending on the vibe I get. Humorous answer: You're EXACTLY the type of person that would get the most benefit from a practice! Metaphysical answer: Ah, yes, but are flexible in the mind?
Both are equally valid for the type of yoga I practice as a student and as a teacher. The classes I love to take are those that impart some piece of ancient wisdom, some insight into yoga, some opening of a window (no matter how small) in my mind that lets in some fresh air, and lets out some old non-functional habits. A class that reminds me of nice it is to have my body WORK, not necessarily 'workout' but simply hold me up, sustain me, breathe, stretch, balance. I love to be able to offer that type of opportunity to my students - to learn something new, to take new information with them to their next class (no matter the instructor or studio) so that their practice deepens. And even those classes that are a "workout" that teach me how to pace myself, how to observe how I feel, how to lead with the breath, how to quiet the "monkey mind." (Hot tip: Did you know the definition of yoga? In Sanskrit it's "yoga chitta vritti narodaha." In English that's "Yoga is the calming of the fluctuations of the mind").
I couldn't touch my toes when I started practicing yoga. Pigeon pose was torturous. I cried quiet hot tears more than once in Savasana. But I kept practicing. There was a deep seated joy in finding out how my body could move, even when my body was wracked with inflammatory pain, even when my heart was breaking and depression was around every corner. When I was able to embody a sensation of new strength, or new balance, or new relaxation, or new movement, I celebrated. When I was "stuck" I just worked on the quiet meditation, and let the tears come and go as they needed. I let my open-minded heart show my mind the way...and let go of (some) archaic, destructive, detrimental and/or limiting ways of thinking.
Group 1, don't get into a yoga rut. Keep being flexible in your mind, keep trying new classes, keep continuing to learn. That's what it's all about. We say "we all come to the mat for different reasons but leave with some of the same benefits." Don't limit yourself by forgetting to come to the mat not just with your body, but with your whole being!
Group 2, there are so many of you (us) out there. GIVE YOURSELF THE CHANCE to experience something. Don't be shy. Don't hold back. Ask questions, Seek out teachers that appeal to you. It's a process, but like that other old saying "the journey...starts with a single step," let's say "the practice starts with a single breath."