Are you LISTENING?

Compares to not communicating at all, i sincerely think it is ruder when you talk to a person but not listening  to what he/she has to say.

Me : Hey i was dancing for this charity event and have been training so hard for it. I felt like we're really making a difference for the society.

Friend : Oh that's great! I was doing this and that for the weekend...bla bla bla...bla bla bla...so what is it all about on the dance thingy that you spent time on? It must be fun being you so happening all the while!

Me : *Note to self : never engage in a serious conversation with this person again*

It does not necessary has to be a serious topic it can goes down to as little thing as repeating the question after someone had answered it previously. It obviously shows that you're not engaging at all into the conversation you're having. Can it be any ruder and inconsiderate? 

I know how i feel:

Ignored

Offended

Sad