Here's the background story. In the past couple of months me and my ex have been on and off a bit - one minute he didn't care, the next he wanted to spend his life with me. He always said whatever happened he'd be sad to lose me.
Anyway we were in an "off" period so I went out Tuesday night and he was there too - he avoided me so towards the end of the night I went to chat to him. He was being a bit of an idiot because he was trying to make out he didn't care in front of his friends. I told him if he didn't care to just walk away, he didn't and told me he cared a bit. In the end I got fed up with him and he said he didn't want to be with me and went home.

I've gone NC with him since, to be honest its kind of a relief to get out of the whole on/off situation. However, every other time he's always text me later or the next day, this time nothing. I want to heal and move on but it's still kind of upsetting me in the back of my mind that he doesn't seem to care.
He blocked me and deleted me on msn but kept me on Facebook, I assume to keep tabs on me. He obviously found out that I went out Friday night and had a great time, I was chatting to one of my old friends who's a guy (ex never liked me talking to him) so he obviously found out, got pissed off and has just deleted me on fb too.

Is it so bad that I wish I knew if he even cared that I was gone? No official goodbye? Not a single text since he walked away? I know its only been 5 days but I keep hoping for some hint that I did mean something to him!

Sadly in break ups ( for good break ups) there is not a final good bye and we often "wish" a lot of things. In the end, it is only ourself we hurt when we keep wanting something from another person they are not willing to give us.

The off and on, ( what are the reasons for it) is often a sign that there are major issues or the couple are not ready for the relationship

I think he has made his feelings rather plain. He walked away. He has gone NC. You have gone NC. NC just to clarify means No Contact of any type-sending or receiving. He may be hoping for some sign that you care. Neither of you should give in to temptation to contact the other person. It would probably only lead to more of the same merry-go-round ride.

As Fr_Chuck said, relationships that are on/off have major issues that show one or both individuals are not ready to be in the relationship.

Let him and the baggage go. Go out and reconnect with old friends. Live your life without worrying about him and what he thinks or feels. Once you let go and allow yourself to move forward, I think you will find that you really don't care what his opinions are.

It isn't wrong to want him to care, even just a little bit. But, there are no rules that dictate behaviour, and he is who he is.

I think this may have come as somewhat of a shock to you, as prior breakups have always resulted in eventually getting back together. I would have expected him to text too.

When he didn't, and took additional steps, that is new, and it is also final. While things are still fresh, I wouldn't doubt that he will contact you, and that is where you need to be ready to respond.

I agree with Cat and Chuck that it's a good idea to use this time of NC to really take a good long look at your life. If it is time to make changes, then start with the resolve to find a mate who is more compatible, and less volitile.

Enjoy your single time while it lasts, and don't look back.