Actually, I have. On more than one occasion.
It goes something like this. I’m lying in bed at night, with the faint lights of my surroundings barely illuminating the room. I’m trying to sleep, but not quite there, when suddenly I notice there’s someone in the room. Someone is in my apartment! And they’re coming over to my bed, and leaning over me! And I can’t move! But wait, I’ll spring into action on the count of three. 1… 2… 3! Poof I snap awake with a thrashing jerk. Yep, I was dreaming. But it seemed so real!
I’m prone to hypnogogic and hypnopompic dreams. Very scary when it’s happening. First times it happened, I didn’t know what was up. I would realize it was a dream when I woke up, but until then it felt real. I felt like I was fully awake, too. Now it gets my heart racing, but once I’m awake I calm down pretty quickly.
And then there was the time I saw a UFO. Until I IFOed it. Looking up in the sky near sunset, looking off toward the Eastish, and catch a bright glint out of the corner of my eye, that quickly disappears. I scan the sky, looking for what it could be. Then I see an airplane flying around, that had turned at just the right angle to reflect the sunlight, but when it turned some more, it was surprisingly difficult to find. See there’s a puddle-hopper airport a couple miles from my house. Now that I know what it is, I can ID them pretty quickly. The other day saw the same thing again, this time looking northwest. The plane was some distance away, so the bright flash stood out but without the light, it practically disappeared just over the treetops. Very difficult to spot unless you know to look for it.
And then there was the almost UFO. One day driving to work, as I pull out of my parking lot someone releases a cluster of helium balloons tied together. I watch them float up and away, carried on the wind. I then drive off and make a large circle, headed eventually north. As I’m approaching work, I catch an image of something flashy and odd moving across the sky, changing shape. If I hadn’t seen the balloons earlier, it would have been difficult to identify.