I have seen 3 UFOs in my lifetime, the last time I was about 36-37 years old out in the middle of nowhere on some old back road between Chico and Willows (in northern California). It was right at sunset, and they grow a lot of sunflower seeds out there. They had just harvested & some of the giant sunflower seed heads were left on the ground, so I had pulled my car over to go get one of them. As I was dragging this giant sunflower head to my car (it was about 2 feet across!), what I can only describe as a red "plane" looking thing literally came right over me, stopped, and I felt a warm breeze as it hovered over for me for what couldn't have been more than a couple of seconds. It then moved and hovered similarly over an abandoned house I had passed about half mile back on the road, then went straight up and disappeared. It was the clearest of the 3 sightings I've had, as it was not at night... it was right before dusk.
Of course, when I was younger I got all caught up in the alien/UFO thing, but I realize now that our government/military as well as private companies are always developing new technologies, and what people often perceive as alien craft are, more often than not, some type of new technology still under development. But that red thing I saw out in the middle of nowhere that day was really something else.