One of what I have guessed based on my thoughts about what made humans end up in the world was by an omniscient being. This is the reason many, many religions believe - the existence of God or a similar being, like Allah or Buddha or the Flying Spaghetti Monster. 

The questions that are directed on this reason are, you guessed it, Who, What, When, Where, Why, and most of all, How.

Who made us?

The omniscient being.

What were we made of?

Dirt, most people say - but the real truth is probably matter.

When were we made?

Probably around when time itself was created.

Where were we made?

Nowhere - not even within a vacuum. The ultimate nothingness. The ultimate nothingness has no color, no air, no nothing. Nothing at all. Just the fact that humans cannot imagine this is the proof that we will never be able to figure out who made us, if there is anyone who did at all.

Why were we made?

We may never know - obviously. We may have been made for mere entertainment - just look at the popularity of Godus, a god simulator game. We may have been made to extinguish solitude and loneliness, as the omniscient being may have been very likely alone before he made anything - however, that may be not the case, as loneliness may not be an attribute the being is able to have... or decides to have. After all, it is likely the being himself made loneliness at all.

How?

Oh... boy. The most difficult one to answer.