What unknown's and unexplainables do you believe in?

Life somewhere in the universe, outside of the Earth. Maybe I'm just a bit romantic, or it is wishful thinking, but I think/hope that we aren't alone, because that would be just boring, and quite offputting, knowing the size of the known universe. Not ET, not little grey ones, just life, somewhere. *stares at the stairs with a longing look*

I only believe what I can see first hand. However... That doesn't mean I'm not open to the possibility of aliens, the supernatural, gods and so on... But until I see something first hand, all I can do is sit in the middle, unable to prove, or disprove the existence of anything.

Recorded sighting of an apostle for a deity
Recorded sighting of a spirit entering a man's body, causing him to lose focus, but then he fights the evil spirit off

I had some others on my mind, but forgot. Might update my list.

Once I managed to insert USB correctly into my PC on the first try. I was there when it happened

If something is not proven and there is no real evidence for it, I think it's simply unreasonable to believe it. The UFO you saw as a kid was most likely something else, like a weather balloon. There is no evidence for intelligent alien lifeforms, so we have no reason to think otherwise. That doesn't mean we have to completely rule out the possibility. Based on how big the universe is, I don't think it's unlikely that there is intelligent life somewhere out there. But it's extremely unlikely that it exists here in our solar system, and that aliens spy on us and abduct us. Those are just silly stories of people who misunderstood a situation (or who want attention and simply lie about it).

After the rejection of four magazines, to have our paper published we had to convince three scientific referees, wich implied additional experiments to our original submission (this translates to months of work added to our already long project)

And this was on something as mundane as protein aggregation in vitro. Imagine the amount of the evidence required to demonstrate something like the afterlife or extraterrestrial intelligent life. Nobody says that is not possible, but there is no evidence yet.