Military Ghost Story (with illustration)

This is the one and only time in my life I'm certain I saw a ghost. Time: 2:45 AM, over ten years ago Location: Next to the entrance of a stadium attached to a military airport in Taichung (You can still see the guard post on Google Street View as I'm writing this). The incident is roughly described in the image. At the time, there wasn't any sound at all. I was just sitting there, spacing out, waiting for my shift to end, when a shadow appeared on the wall. Not realizing it was a supernatural event, I just thought the inside of the shadow was a bit bright and pretty (?). It wasn't until the shadow completely disappeared into the darkness in front of me that I snapped back to reality. When I looked back, there was nothing there 🤔. Then, I went to the road to check the height of the shadows. Assuming they were about my height, they were indeed moving along the road. After confirming, I happily told the junior soldier who came to relieve me about it, patted his shoulder, and went back to sleep 😂. What I might have seen if I had turned around immediately is one of the things I'm most curious about in my life 😮💨. Unfortunately, perhaps because I was too excited about my first ghost encounter and spread the word too widely, I was transferred elsewhere not long after. But seeing a night sky with no light pollution, where stars had a sense of depth and the moonlight cast shadows, at my new location is another story.