Anyone ever seen a UFO?

[Guaranteed]

I went outside tonight and looked up at the moon. Suddenly from the west I saw this object that at first looked like it might have been a helicopter, but when I looked closer I saw there were a bunch of twinkling lights on it that made it look like it was spinning. It definitely looked circular.
Then the way that it moved- it was moving above the clouds, so it kind of made sense that I couldn't hear anything (although I listened very closely, and usually if there's a helicopter anywhere in the area you can hear at least a faint sound of the rotor blades). It moved very oddly- it seemed to dip a couple of times very quickly. And at first it seemed to be moving fairly slowly...but then it moved over to my east side and from the southeast it made very quick work of getting directly east of me. If the thing was so far away it must have gone at least a mile in a matter of five seconds.
So then on the hope that it would stick around I ran inside and woke up my girlfriend. She came out and didn't see anything. She thought I was nuts. Then I went over to the other side of the house, and I saw a bright light a number of miles off behind the clouds to the north. We couldn't see the object, of course, and we only saw the light moving for my fifteen seconds before it went way behind the clouds and to the horizon.
Anyway, maybe I'm nuts.
But has anyone else seen anything like this? Just wondering- you guys are smart folks and I trust your judgment. You don't believe just anything.