It's perhaps not the spookiest thing, because members of my family, both this generation and the past, have experienced stranger things, butthis is the one I remember the best right now (I have posted it before, but repeat it),
I had an experience a couple of years ago, one late evening, I had shared a bottle of white wine with my wife (I know that "tunes down" the whole thing, but man! half a bottle of wine produces nothing like that ....), she went upstairs to go to bed, it was 10:45 at night, and I let the dog out in the garden for her usual you-know-what. 30 metres away is a small road, there are houses around, and 30 metres down to my left another small road departs in a 90 degrees angle from the one passing my house.
I had been out 10 seconds, when suddenly VERY loud noices were all around, in the air sort of, but very close to the ground, like - please don't laugh - Santa Claus with his sleigh came down the road, like sleigh bells, but much louder and more distinct, roaring. After some seconds, I managed to make out the direction, and the sound came down the road, from my right towards the left, in a way following the road but in the air above it yet very close to the ground, and it took a fraction of a second to pass in front of my garden. Like "Santa's sleigh" making 200 miles per hour down the small road, whizzing past my garden, and then it made the sharp 90 degrees turn to the left and disappeared down the other road to the left. I looked for my dog, and she had sought refuge under some bushes in front of/underneath my porch and refused to reappear. I had to walk down and half-way drag her out of the bushes, she hastily did what she always does at night and ran indoors and hid under a couch. As she so did, the sound reappeared from my left, from this other road, and obviously this "thing" came back the way it had left. As the sound became very loud again, and became an all-consuming roar again, I followed the dog ........ The second I closed the door, it was totally quiet inside, although one can hear the bass from car CD players if they play loud enough on the road, and of course the sound of cars - but now it was dead silent outside.
I sat up in bed half the night, talking with my wife, I had the window opened to hear if any more sounds came, she had heard nothing, and our / my guesses ranged from demons thru angels to the "little people" living the Earth together with us, albait invisible .......
Now what was this? Loud, pointed sleigh-bells sort of, passing with incredible speed and invisibly, making sharp turnes and then reappearing?
No cheap wine, no flashbacks from earlier "happy" days, no special mood - just plain .... I don't know.
