I grew up believing there were no such things as ghosts.
I was taught that every unusual event had a rational explanation. If I couldn’t find an explanation, it just meant I hadn’t found it yet. My father was firmly in the camp of not believing in anything supernatural. We enjoyed a good ghost story, but we knew they were just stories.
Yes, we believed in God and we believed that God could do anything he wanted, but we were taught — at home and at school — that God wasn’t acting in supernatural ways in the world since the end of the Apostolic Age (which was covered by the second half of the New Testament). It was a nice, neat little theological explanation by which we could believe God did miraculous things back then — but there was nothing supernatural today, either good or bad.
That all changed — at least for my father — shortly after my grandfather died. My father’s long-time belief that everything had a rational and natural explanation changed after he was visited in the night by my dead grandfather.