What I miss...
Spending time in a non-English speaking country, the conversations around me were white noise. I didn't know the language, therefore I didn't (whether consciously or unconsciously) listen to, process, judge the conversations around now.
Now I'm in the US where everyone speaks English, and I am bombarded with noise! Conversations swirl around me, which I must laboriously block. At times it feels like a dozen smoke detector batteries all failed the same night! And the garbage truck in backing up.