My English... still ...

After two years of my life in San Diego, I still face some embarrassing situations once in a while.

This morning, when I was standing at the checkout counter in Albertsons, a guy who was packing my shopping into a plastic bag told me something unclear in a low voice. I bluntly asked him, "Sorry?" and he repeated in the same tone of voice. I did not catch it, so again, asked him what he just said to me, moving my ear close to his mouth almost in a foot distance.

He shyly mumbled, "You have a good day..."

That's it?? Didn't I catch that simple sentence????
He was a young African-American guy, looked uneasy repeating the same phrase three times for me. Blushed and upset, I forgot to say "thank you" and just ran away.

Even after two years, I struggle with English.