Just saw an interesting TV program about past and present mysteries in Belgium.

Crop Circles at Waterloo (yes, where Wellington defeated Napoleon!) are no more a mystery: they're man-made; a guy who calls himself "Cereal Killer" explained with friends how they flattened the terrain...I'm laughing because a friend of mine who is president of an astronomy club close to Waterloo, takes this far too seriously!!

About the 1989-1991 UFO wave, the journalists tested former witnesses with a triangular blimb (with the lights) and at night and didn't succeed as the witnesses didn't recognize what they remember seeing.
It wasn't F117's, AWACS, blimps....Hundreds saw the same thing the same nights, hundreds of km apart from each other and only half an hour apart....

A witness who is an engineer, when asked if he regrets what he saw said a few interesting things: He was happy to witness an unusual event, but frustrated by the lack of explanation.
He saw something that is still unexplained but not unexplainable.

16 years later, still no answer to what happened.