No, they didn't all show up on my wall. But it's facebook, I stopped questioning the logic of it a long time ago, lol.
In my case it's weird, it showed 62 things on my wall last year. I don't think I had 62 things posted to it (especially as I tend to get rid of spam etc). There was something from my sister that was totally out of context too, and she only posted on my wall once ever. In my case, it actually seems like it was some chat messages or something? I don't know. I just hid everything anyway. Nobody needs to read that stuff...