On a similar note, I just finished the book "We Learn Nothing" by Tim Kreider. In it he expresses the following thought:
We each have a handful of those moments, the ones we take out to treasure only rarely, like jewels, when we look up from our lives and realized: “I’m happy.”
It's funny how I've never really thought about those moments and never really considered that they weren't unique to me, but when I read that, I knew exactly what he meant. I have these moments under the same circumstances as you.
the main pub of my hometown, during buzzing summer nights, being with some friends, sharing a card game, a good conversation or just a nice drink.