What should you do when you are having a fairly good day, then you cross paths with someone that is not having a similar day as yours?
The very first thing that you should do is not let the bad attitudes of others change the good day that you are having.
Understand and know that you are not the cause of anything that they might be experiencing.
Do not return the same negative attitude towards them that you are feeling from them.
Speak to them in a caring way to see if there is something that you can do to help them, if the answer is no don't force the issue.