I can't count how many times I've pulled over and offered help repairing a vehicle, tools, a ride, use of my cellphone, water, oil, antifreeze, a jumpstart, and other stuff to complete strangers on the side of the road.
We rolled up one day on a Dodge Caravan with 3 people in it out in the woods, roughly 10 miles from the nearest paved road. They broke their axle about 5 minutes before we pulled up. I asked if they needed a tow back to pavement, the driver said yes. I hooked my tow strap to their van, and pulled them back to the road. They had a friend with a trailer come get it and take it home. The driver kept offering me money, I told him I couldn't take his money, but that he should pass along the favor to someone else.
People are amazed that a stranger would just pull over and help. I just figure what comes around goes around, maybe one day I'll be the one needing help.