This whole thing where we all act terrified of strangers is a societal disease specific to our time and place. There was a whole era where it was socially normal to ask for a ride from random strangers on the road using hand signs, and it ended in part because of a very small number of highly-publicized crimes. For god's sakes, make a good friend of him; at our age, we're almost certain to run into a deficit of friends. And who knows, he just might save your life one day or vice versa, if there's a disaster and one of you checks on the other... or if one is incapacitated and nobody else notices.
Always good to keep an eye out for sus behavior, but trying to be neighborly shouldn't be considered sus imo.
