Ex wishing me a happy birthday?

blondediamond
My birthday passed a few days ago (November 2) and today (November 4) I received a Facebook message from my ex whom I dated for about 5 months and known for about a year. He broke up with me a year ago after my birthday saying that he really liked me as a person but couldn't see us being long term. Since that time I've worked for a few months, dated another guy (we're broken up), and finally started college/university for the program I've been working on for quite a while to get in. In the message he said "Happy belated birthday. Hope you have a good time :)". I don't know what he has been up to since he did this last Christmas by wishing me a merry Christmas and not answering my question about how he was. What does he possibly want? Is he trying to not look like a jerk or is he trying to initiate communication between us. He's also changed his profile picture recently which he hasn't changed since 2007 to a recent picture of him looking all happy and whatnot. Again trying to show/prove something to me? We're no longer Facebook friends since the breakup, so how and why would he even bother to remember my birthday?
Updates
+1 y
Also should I respond back to the message? I was going to a few days later, but I'm sure if this is the smart thing to do.
Ex wishing me a happy birthday?
2 Opinion