Both of the situations you shared in your post did not show respect for your boundaries and feelings are part of one's boundaries. This neighbor was being too forward with his response to you, especially when he said "Love you" because that relationship is basically just an acquaintance. And responding in calling you "kiddo" can actually be considered improper in that you are no longer a "kid". It's one thing to be neighborly, and just be nice and considerate, yet, his response really did not fall in the line of simply being "friendly" and it's understandable you would feel the way you do.

When it comes to your mother, her response of "oh don't let that bother you", simply did not respect your feelings and no one likes to be told not have their feelings and that might be a habit of your mother's that tends to bother you. She could have validated that "yes" that man's response to you was not proper and it's understandable that you are uncomfortable with it.