Yes, I've had many experiences too, and I'm more than 99% sure it's a real phenomenon. I was talking today with someone who said to me that they'd never had such an experience, and they believed it was just some kind of hallucination going on in the brain. I said do you think you'd change your mind if you had one of these experiences? She said no. I said, that's like saying, you don't really care about the evidence. And I guess that sums up many people's beliefs on the subject, at least in the developed world. Here in Mexico, almost everyone takes it for granted that ghosts exist, or at least that it's a subject to taken seriously.
I think a lot of people will use their belief in God to say that ghosts do not exist as well, which is kind of funny if you think about it.