White light up in the sky moving faster than usual

I was walking then looked up to the sky to admired the beautiful sunset and beautiful orange clouds when I saw a white light in the sky, not bright white light, just an unusual thing to see in the sky, (different) and moving faster than usual with no smoke behind the white light, then after 5-6 seconds, it disappeared !! It was like this light knew I was watching it !! Well, thats how I felt anyway lol. There was a pizza guy dilivering a pizza at that moment when I was looking at this light, and was just about to say to him to look up to witness what I am witnessing, but it had to disappear didn't it !! Not sure of the shape of the craft because it was so high up, the only way I can describe it is a white light.