Ghosts: Photographic/visual anomalies.
UFOs: Photographic/visual anomalies.
Astral projection, zygomancy, etc: You're either lying or fooling yourself because you want it to be true.
Gods: You work hard to gain enough money to pay for cancer treatment, saving your life. You give your god credit for an non-obvious reason.
Conspiracy theories: People really like hearing about conspiracies and deep secrets. That's why The DaVinci Code sold so well. People sometimes like them so much that they look at evidence but arrive at the wrong conclusion.
Everything else: You don't know what the hell is going on, so you fall back to fantasies about supernatural phenomena which are not based on reality in any way.
But seriously, there's loads of intelligent life. It's just not screaming constantly in all directions on the handful of frequencies we search.
There are a lot of graduate-educated young-earth creationists.
Please remain rational in the future rather than jumping to conclusions.
