It’s not that we dislike you. We just don’t like you.
See, we don’t know you. Our interaction with you so far has been limited to selling you “un pain au chocolat s’il vous plait” or being in the same metro car with you or passing you on the street (more likely standing in your way on the street). At this point in our relationship, your presence does not naturally fill us with joy or bring a smile to our face. Also, we do not really care if the rest of your day is nice. We do not wish you ill, but if the rest of your day is miserable, this will not affect us. Tomorrow, if we see you again, regardless of how your day was, you will still smile insanely, ask us what is up and then instantly change the subject or simply walk away before we have a chance to respond.