OK, I'll own up. I'm not a professional pilot and only an ex-controller. But.......over my 40+ year career I have seen a few UFOs. I have reported some of these events, well, one actually. If I'm going to be completely honest, I actually saw one last night - lights in the sky, and I could not work out what it was. But then I put my glass of wine down, thought for a few minutes, realised that I'm about a mile away from Schiphol airport, so it might have been an aircraft.....but I really don't know for sure. I reckon the pilots answering this question and saying they've never seen one are covering things up.