What did I do?

I don't get it.  My friends know I'm at my apartment and know that I don't have anything to do today.  I ask them to call me if anything happens.  No one calls.  Only later do I find out that they went to see a movie and the text I get, "Sorry I didn't text you back..." It's just kind of frustrating, because the first thing I do when I know something is happening is call other people.  It just sucks to feel left out.