I haven't told many people that I'm having therapy (or that I have PTSD!) but I did experience this kind of misunderstanding with a good friend.
She's had therapy (may have been counselling) in the past and found it very helpful - it basically gave her the impetus to end a relationship that wasn't working out and also lead her to quit her job and live abroad for several months. All good stuff.
So I shared my starting therapy with her just so that I felt a bit more like someone would understand what I was doing and would be able to empathise with the odd dynamic of a therapeutic relationship etc. I've told her I have PTSD and that I'm doing trauma work in therapy, but no other details about the trauma itself (my therapist is the only person I've told 'my story' to),
Anyway...it quickly became clear that my friend just didn't get it. And it made me really realise how different trauma therapy is from other kinds of therapy. Which I suppose is pretty obvious but, what can I say, it obviously wasn't to me at the start!
She texted me every week asking how my 'head work' was going, asking if it was helping, asking if I was making progress etc. The truth was, at that point I was dissociating loads in therapy (I still do) and barely spoke. So often it felt like I wasn't making any progress at all - despite intellectually being impatient and wanting to move things on, I was just so mute and stuck. And when I tried to explain this to her, she just said 'After all this time??' (it had been a few months!) And then told me to get a new therapist because this one obviously wasn't working because I 'shouldn't be finding it this hard after all this time.'
Ha! That's when I really knew that we just weren't going to be on remotely the same page so I decided there and then to not speak to her about therapy again!
It can be frustrating. And isolating. I just wanted to think that there was someone who 'got it.' But most people don't. I guess that's why we come here :-)