this happened to me.
8 years ago i was a noob with a POS $15 bike and got a flat 1 mile from my house.
another rider stopped and asked if i needed help.
i told him i had a flat, and no tools to repair, but i didn't live that far away.
he insisted on replacing my tube and after repairing my tire he refused my attempts to pay him.
he handed me a business card with his # on it and said if i wanted to join him and his group on a ride i was welcome any time.
i now live 75 miles away but i try to go on a 50 mile group ride with him at least 1 time a year.

whenever i ride i always have 2 tubes, a patch kit, 5 co2 inflators, mini pump and a few often used tools.
every year i end up installing at least 2 tubes on other peoples bikes.
when they want to pay me i just tell them stop and help another person on the trail.
i also have given my # out a few times. and have ridden with them more than once.