Fine and dandy

I was in the supermarket a few days ago and my shopping was more than I thought it should've been. The checkout woman looked at the till screen and drew a blank. I said, I'll check it when I have the receipt, I'll need to sit down first, and she said, No, you can do it here, love, and I said, I can't, I need to sit down to check, I'm chronically ill - my head had shut down - and she said, Oh, tell me about it, I'm never away from the doctor's just now! I'd heard her tell the previous customer...