On one of my regular visits to Prestatyn I was in Tesco and about to pay at the automated "self checkouts", which are, of course, ddwyieithog (bilingual). Then I departed from my usual conventions and decided to use a human-staffed checkout as the checkout operators seemed under-occupied and I didn't want to think of them being replaced by robots.
I decided, pretty much impulsively, to make a brief comment about the situation in Cymraeg:
"Well i mi ddefnyddio'checkout dynol, i gadw chi mewn gwaith" ("Best if I use a human checkout to keep you in work").
Remembering that I was in Prestatyn, I was expecting the usual "sorry, I don't speak Welsh" - and ready to explain the opportunities for fixing that potential issue. But, to my most pleasant surprise, the checkout lady replied in good Welsh, but a bit self-dismissively, explaining that her Welsh was a bit rusty these days. I obviously commended her on both her good Welsh and the fact that she was speaking Cymraeg to me as a customer, and told her about the local conversation group I was on my way to.
Finally, I explained that I currently live in England (Lancashire) but my Grandad came from Wrecsam. Some people at that point might realise or guess that I was a recent learner, but I don't think that she did. It did feel like I came across simply as a guy who speaks Welsh, even when he is in Prestatyn.