Working at the post office, I'm used to dealing with a moody public.  So, when one irate customer stormed my desk, I responded in my calmest voice, "What's the trouble?"

"I went out this morning," she began, "and when I came home, I found a card saying the mailman tried to deliver a package, but no one was home.  I'll have you know, my husband was in all morning!  He never heard a thing!"

After apologizing, I got her parcel.

"Oh good!" she gushed.  "We've been waiting for this for ages!"

"What is it?" I asked.

"My husband's new hearing aid."