The only experience that's ever happened to me that I just truly couldn't explain happened when I was 11 or 12.
We were living in my first of 2 childhood homes. It wasn't very old, but the previous owner had hung his self in the shed behind the house (I'm not sure if that's related at all, I just always feel compelled to tell people that before this story). But anyway, I had been at a friend's house who lived across the street and I came home a little late to have some dinner. My family was in the living room watching tv so I went to the kitchen to eat by myself. I believe we had ordered pizza and it was sitting on the kitchen table, so I just sat down there and started eating. The main lights were off, but the light above the kitchen sink was on, which gave off enough light to see what you were doing. Anyway, our kitchen table sat right across from some of our back windows, and there was enough light in the kitchen to see reflections in the window. And while I was eating, I just happened to glance up and look at that window, and I saw my reflection.
I was sitting perfectly still, but my reflection was shaking. I just assumed there was something causing the window to shake at first, but then I realized it was just the arms of my reflection that were shaking. And I took the time to actually look down at my arms to see if they were shaking, and they weren't lol. Needless to say, I had lost my appetite by that point lol. So I got up to throw my paper plate away. I walked to the garbage can, then walked back by the table (still not sure what exactly I had seen), and looked into the window again. And, this time, in the reflection, there was a man standing behind me. I can't remember what he was wearing, and I never got a good look at his features, but there was a figure of a man as plain as day. I stood there for what seemed like 30 seconds (but was probably more like 2 or 3) before turning around and finally flipping the main light switch on. And when I turned back around, there was no longer anything abnormal about the reflection.
That was the only time I ever personally experienced anything in that house (although my mother and sister both had experiences of their own, and oddly enough, both were isolated incidents like mine). I haven't witnessed anything since that night in regards to the paranormal, but it definitely opened my mind up, and to this day, even though I am in no way religious or superstitious about anything, I refuse to label the topic of paranormal experiences as just outright false. I vividly remember not wanting to sleep by myself that night lol. And even at that age, I was a pretty "secular" person.