You don’t have to be in the military to spot odd objects — or to be a credible witness.
I was on the roof of my three story apartment building to watch the sunset five decades ago, when I saw an aluminum colored sphere the size of a small billiard ball progress slowly in a straight line across the sky about 100 meters above me. If the movement had been less steady — it was very steady — I would have discounted it as a balloon caught in the breeze. (There was no breeze at the roof top level.)
I followed it until it was too distant to see any more.
Since then, I have always thought it odd that the universal assumption about these UFP is that they are either our size or bigger (maybe child-sized like ET). There is no reason they could not be significantly smaller than us.
I am not saying they exist, nor that what I saw could not have some prosaic explanation. Just that what you see often depends on your search image. As Schumacher said, “Small is beautiful!”