I learned about the way people react long ago.
A guy had a fire in his car. He'd opened the hood (don't) and the fire was raging. He was trying to flag people down but everyone just looked and drove on.
I stopped. I jumped out of my truck with a fire extinguisher - he was so happy!
I put out the fire, not too much damage had been done - yet.
He was so appreciative - until I asked for the $5 to refill my extinguisher.
He cussed me out, called me every name he could think of!
He said I did it voluntarily, he didn't ask me to help!
I thanked him - he was surprised - not what he expected - I thanked him for teaching me how human nature is - complete aa----s!
If I'd had a lighter handy, I would have relighted the fire!
Off road I help as much as I can - I carry a welder and other stuff for that. But if I have to put in one of my spare axles or other parts I carry as spares, I make it clear to them I want reimbursement for it - before it gets put on (unless it's one of the folks I wheel with.) If they object then "oops, I thought it would fit but it won't.")