When I was at the cash machine today, a receipt had fallen out of my bag and a lady yelled over to me from about 50 meters away to tell me “you’ve dropped your receipt!!!”. I’m not being funny but a receipt really doesn’t qualify as something you should tell someone they’ve dropped! I was raging! I felt like she’d just told me I’d dropped my dead biscuit 
Ten pound note - Yes, yell!
Receipt - not so much.