A strange pulsating light

So, I was in a supermarket recently when I noticed something rather odd. There was a pulsating light illuminating part of one of the shelves. I assumed it was a faulty light but, looking around, I could see none. What is more, I saw the same light illuminating another area of shelf several metres from the first. While not exactly paranormal, it certainly appeared inexplicable!

Eventually, after looking around again, I identified the source of light. It was the sun reflecting off the vibrating window of a bus outside in the street. The bus was waiting at a traffic light. I would never have guessed that to be the source of the pulsating light if I hadn't seen it. So had I not noticed the bus, or if it had left before I looked outside, the light would have remained a mystery!

I think many anomalous reports could be explained if the witness had just noticed more about what was going on at the time of the incident. The problem is that witnesses have a natural tendency to look only at the oddity in front of them. They tend not to notice what else is going on at the time including things that might explain the anomaly.