I just turned around for 1/2 a second, and it was GONE!!

I was walking home from work, it was a very clear day out. And just over a building,  about 4 stories high, I saw this object. It was  mettalic colored and it had flashing lights on the bottom of it. I can't quite recall the color of the lights, but I remember lights flashing. It was just hovering there for what seemed about 5-7 seconds. I froze, almost like I couldn't move even if I wanted to! Walking behind me, was a man in a 3 piece suit with a briefcase. So I turned and asked him "did you just see that?"  But he acted as if I wasn't even there. Like he didn't see me! By the time I turned around to see the UFO, it was gone. I mean GONE! As I mentioned earlier, there were no clouds in the sky at all that day. So where could it have gone in the half a second that I turned to talk to that man? And how could something that was just hovering, build up that kind of speed so quickly? I kept walking home, not taking my eyes off the sky. I remember being very frightened.  Like when you think you've seen a ghost. When I walked in the door, my cousin said I was very pale. The 1st thing she and her husband said was "you look like you've seen a ghost!" I don't drink or do drugs! So I know that I saw something that day! I just can't understand why that man didn't it, or ME at that!!!!
Witness indicates that date of incident is approximate.  PD