It happens..... a few years back my son was training for his up coming bicycle ride across Canada. One of his training rides took him up the Island we live on about 40 miles, he thought he could hop on a ferry and ride across the inlet then back the 20 miles or so to home. He was waiting at the small ferry terminal, no staff there, chatted with a "old guy" as he put it... like maybe 50 or so..... told the fellow about his upcoming ride for a charity and stuff. The boat showed up and all 20 cars and my son with his bike go on. Staff member told my son cash or Visa card... my son only had a debit card, I think the fair is $3 for him. Fellow who he had been speaking with got out of his car and paid for him. My son being the person he is said.... can I please have your name and address to return the money to you. The man did introduce himself to my son and then said.... pay it forward.
My son rode his bicycle 7000 kilometers across Canada raising money and awareness for The Brain Injury Association of Canada... upon his return he even auctioned off his bicycle and the money went to the charity.... I think he is paid up.