Then, there is the Urantian theory that earth is a prison colony for the rest of the universe and that our human body is the prison garb.
To me, this does make sense because we do treat each other very much as people treat each other in prison with all the power struggles, anger, etc.
There are many theories, and many of those are certainly interesting. I have only known two people who truly saw something unidentified. Both are/were engineers not given to stirring the pot to keep their lives interesting. Neither claimed that what they saw was from space, instead only emphasizing the "unidentified" aspect.
One person was in Seattle in 1947 and was waiting at a bus stop on an unusually clear (for the area) day. He saw a disk floating just above the trees. It was there for several minutes, then took off straight up for a bit, and then flew off at a 45 degree angle. He said that the Seattle paper, the next day, listed 1200 witnesses, many of whom were trained such as cops and military. He said that most people simply thought it was some military development for WWII. He also said that he has never seen anything fly like that, and at those speeds since.
The other person saw three glowing balls about 3 feet in diameter, in a line perpendicular to his truck in Northern Minnesota when he was in high school. Two of his friends were in the vehicle at the time. These things stayed with them for quite some time, leaving only as they approached Camp Ripley, a military base, and rejoined the truck after they had passed the base. One of the three guys got so freaked out that he has spent the rest of his life pursuing information about UFOs. The other just took it in stride. I found some information online about "Foo Fighters" that were commonly seen by fighter pilots during WWII and the pictures, he said, were identical to what he saw.
I have left out some of the descriptive, but non-essential details in both stories because I don't feel like writing a book-length post, but my descriptions here capture the gist of it.
I believe these people saw something, and respect that they don't go off making weird claims about it, being careful to stay within what they know, rather than beefing up the story with wild claims. We will probably never know the origins of what these people really saw.
Tony