Alright lets get started, shall we?
(I'm below the age of 18, So this wasn't long ago that it happened.)
So, I remember that my best friend Tristan told me about a co-op game about zombies, and I don't remember what else he said but he told me about this in around 2004. (The time Left 4 Dead started going into development.) So I was only about 6. And he was like 8. (Yes, I know... little kids shouldn't know about this, but what ever.)
So he tells me about this, then 4 years later, i'm over at my friend Bryce's house, and we are on the Xbox dashboard. So we go to the Xbox marketplace, and we see 'LEFT FOR DEAD' up on the demo section. I'm like, "DUDE! Go click on that!" And then we click on it, and we read the description, and I think to my self, Wait a second... That was the game Tristan told me about a long time ago!
So yeah, We played it, and then my 16 year old sister started to play with me on the demo, more then we did on the game, I remember we never wanted to finish the Subway mission, so we camped out at the top and just messed around.
Good times. Good times.