Always feel like a jerk when I can;t understand someone's accent. You say "pardon me?", they repeat themselves and you still don;t understand and just kinda nod like an asshole hoping it wasn't something you needed to respond to...
Trust me, it's even worse when you're hearing impaired like me. I rely so heavily on lip reading, but some non-native speakers speak so differently that lip reading doesn't help me much. I feel ya.
Loud car stereos and parties have also made rely on lip reading... I can't understand people who speak clearly in the same dialect as I do if they are even looking away from me.