Discussion on question by MindX: In a cemetery, what evidence could be found that humans were intelligent and had technology?

I feel the timescales are pretty far off. There must have been some major global devastating memory and culture loss for this to even make a tiny amount of sense, considering how well we know the history of the human race 3000 years back. We even have books written back then (I've read three). I find that this would be easier to answer if you include details about why everyone suddenly forgot everything.