I tend to get some pretty cool dreams at times and I'll write down the best ones to use as inspiration. Recently, during my fever-laden headcold, I dreamed about reading someone's post on a message board and I thought (in the dream) that it should inspire an idea for me.

Waking up, I wrote down the dream and the details of the inspiration.

Today on a messageboard someone posted almost the same exact post. This is of course nothing short of WIGGY, and I mentioned to that post about my Deja Vu moment and the dream that inspired an idea.
Later today I told that story to someone and they said that they felt like I already did tell them this story. He even mentioned a detail of the inspiration I didn't tell him yet. It wasn't 100% correct, but close enough that it made me go "HMMMMMMM....."

Dreams are weird.