In the urban parts of New Jersey, a good deed would draw suspicion from some people, like they were wondering what my "angle" was.
I just said that, as a Boy Scout, I was supposed to do at least one good deed every day ... and I was WAY behind on my quota".
That seemed to satisfy the skeptics.
I swear, I NJ, if you walked up to a stranger and tried to hand them a $20 bill, they would freak out and assume you were somehow setting them up for a mugging or some complicated scam.
When I slowed my car down down approaching an on-ramp, to let someone pull into traffic, their heads would spin around looking for the cop car or out-of-control truck that was the only reason they could CONCEIVE OF for anyone slowing down to let them get in front.
Eventually I learned to relish the rascality of teasing NJ drivers this way. Just be polite and considerate: they will NEVER figure it out!