Why are some people just plain rude and obnoxious at times ?
Well, different things for different people. Everyone has a bad hair day occasionally, and, well, unfortunately, the rest of us suffer for it. I know I’ve caught myself being ill as a hornet, and winding up having to apologize for sticking my foot right on in my mouth a time or three. If you’re talking about someone who’s just that way, well, sometimes they just, as us Southerners say, “Don’t have good raising”, and weren’t taught manners. I agree with the other poster who said it doesn’t cost a thing to be nice, and politeness is the grease on the wheels of life. Sure is a lot more pleasant to be around crowds of folks if they will say “Excuse me,” or “pardon me” when being bumped around and such.