There are two types of people in this world: those who believe in ghosts and those who don't. The skeptics and the true believers, if you will.
Whether you're a skeptic or a believer, chances are you feel very strongly about your stance. People who believe in ghosts are certain they saw what they saw and it was real. Folks who don't believe in ghosts are sure people are just seeing things and that all paranormal activity must have an explanation.
The figure you saw in your peripherals could have just been your mind playing tricks on you. The lights turning on and off can be explained by an electrical error. And your keys not being in the place you left them could be you not being able to remember moving them because you're so, so tired. Right?
But sometimes a skeptic can become a believer, and this happens when they experience something they cannot explain. These stories are often chilling, sometimes moving, and usually at least a little spooky. And lucky for us, reddit user Musician_Moneyless asked, "People who used to not believe in ghosts but do now, what changed your mind?" And the internet delivered. Here are 13 goose-bump-inducing answers.