I believe there is so much more to know about the universe and humanity and that some of it is already know by a few.
I suspect that there are secrets about our past and our present that would blow people's minds.

Yeah, it it's the only thing that makes any sense to me.

I'm just wondering how it would be if a time traveler arrives in your time. He must come from a different future that will never happen and that you will not be aware of. On the face of it there will therefore be no consequences for you beyond the fact that a dude has just arrived out of nowhere and claimed to be from an alternative future.
The complexity comes when he brings technology or information with him that could change everything going forward. This means that inter dimensional/timeline beings would impact on your existence from your point of view. In reality, the traveler would be giving up his present to make a new one and he will be the only one aware of the change. He will also remember his original time as it still exists in another timeline. In his original time, he will disappear in the same way as if he had died and that will obviously effect his and his original worlds potential future.

Weird.