Accessing old postings?

I just tried to find a thread that was started about a year and a half ago with no luck.

Is is no longer possible to access these old threads or is there a way to get around it?

I imagine the memory it would take could be pretty large so I completely understand if they had to be deleted. There were so many great threads though, kinda sad if they're not there anymore.

Thanks for creating my favorite internet site!!