The summer of 1978 or 1979 I worked at a high-end audio dealer in the Georgetown neighborhood in DC. What appeared to be a "smelly homeless guy" and his friend were enjoying our Bang & Olufson display; all the other salesmen left the front of the store, instead of engaging these two customers.
Long-story-short, the "smelly homeless guy" was a neurosurgeon who was on duty so long, he hadn't shaved or probably showered for a few days, catching whatever sleep he could, in between surgeries.
I sold him $38k worth of equipment.
He returned in a few weeks to snag a pair of Yamaha NS1000's for his garage, which was home to his Rolls, Ferrari and Benz.
You never know who will walk into your shop.