I think I may have seen a few UFO's in my life.
The first, while having a cigarette in my brother's garden, I looked up at the stars (I always have done so) and noticed one, brighter than most, moving fast across the sky. I called my b/f to come outside, he did, and we watched the 'UFO' move across the sky in a straight line, turn on the spot, and travel in the opposite direction in an erratic fashion, but also twice the speed of before. This was above Blackpool in the NW of England.
Since moving to the South of England, I have seen the same or similar, up to six times in one night of watching, some of these have been alone, but most have been while with another person!