Yeah, I totally see what you mean. I actually wanted to see what people thought of Number 13 as a whole and not necessarily Friday the 13th (I just happened to post it on Friday the 13th, haha).
I mean it can be any number really, some people have a 'Number' of some sort that they bet on or see pop up all the time. Maybe it is all in our heads though and like you said, we're inclined to look for patterns? I think in my case I haven't noticed it until about 4-5 things have happened on that day of the month in the space of 4-5 years.
And absolutely, I just got my tickets so can't wait to go!