Serious question - have you ever seen a ghost? If so, why are you certain about what you saw? Could it have been a natural phenomenon? I ask because something I saw is preying on my mind. I was driving through a village on the East Sussex border one afternoon last year, thinking of God knows what, radio on, when all of a sudden the car filled with the smell of fuel (which makes me feel ill ). I then realised a plane was flying very low left to right across the road, so low that I thought it would crash. I couldn't see any markings on the plane but I remember the shape very clearly. I don't remember whether or not there was any noise, but I was so shocked I brought the car to a standstill and looked back across the road. I realised that to my right the land fell away very sharply, so it would have been possible for a plane to fly over me and then clear the trees heading off over the valley (i think) except that I couldn't see any plane. I honestly stood there and listened for an impact. I could still smell this incredible odour of aviation fuel (like when you are crossing the tarmac sometimes on a small airport and the wind catches you, only much stronger). Never thought about ghosts before, but I still wonder what exactly I saw that day.