I can't understand boys,help!

A boy sometimes phones me and talk to me.
Sometimes he doesn't have any reason,because I asked him and then he said it is so boring,can't I phone you?....
of course,I said that is no problem..
but now,he doesn't phone me anymore...
I didn't care before,but now I don't know why...I care about that...
when he saw me,he knew I was here...but he ignored me and then go on to talk with his friends...