If you want to be sure of unusual thing such as aliens or UFOs,
then you have to think about it from an unusual way of thinking.

There is no UFO and also there is no alien,
at least not in common mind nor reference.

If you want to find wilier race by common sense,
then you have just narrowed your searching area.

When we do stargazing, we stare at the stars...and many other things which we have presumed commonly as stars.

If you begin to find the alien by using common sense, then you have just narrowed your searching area.

If I tell you that I have seen the alien, you won't believe me, or at least you will ask for my explanation. If I explain to you in my understanding, more questions will raise in your mind. Eventually, you have to see them yourself and perceive the experience with your own understanding. After that, you will feel eager to tell people about it.