People are free to fill this fulls of holes, flame me or whatever. But yes I do believe in ghosts. Why? This is why.
When I was around 13 or so my family would often visit my aunt's farm in Iowa. Not much to do at a farm in Iowa, so me and my sister would just go around looking through old barns or whatever. Well one day we were playing in a camper near a wooded area. I was in the back, my sister up front, I turned and saw her staring out the window with a dumbfounded look on her face. I ran up to see what she was looking at, looking outside I saw a man with short sandy blond hair who was wearing a Victorian era suit. He turned, looked at us, smiled, then walked into the woods. My sister and I ran inside without saying anything to each other. I told my dad what I saw, my sister told my mom. Remember we had not said to each other what we saw. My parents talked to each other, turns out we both described the exact same man. Well my uncle and dad both went out looking around and couldn't find anything. Several years past and I eventually just passed it off as a coincidence, a trick of the light going through some trees or something. But around the time I was 15 my sister and I were at a local park around 8 at night, it was getting dark and harder to see outside of the street lamps. I heard my sister shout and ran towards her, asking her what was wrong. She told me she saw the man again standing under a street lamp. She said he did the exact same thing. Looked at her, smiled, then walked away. Not wanting him to get away if it was some random guy, we ran to where he walked off, but found nothing. This happened one more time last year when I was 18, she saw him outside of one of the windows of our house, once again smiled and walked off. Couldn't find any trace.
That is why I believe in ghosts. Personal experience. As I said, believe me or don't, say what you will. Won't matter to me.