creation of the universe.

this has been bugging me lately, I guess because it's a question without answer (yet).

How was the Universe born? It seems all so impossible, and yet here we are. Anyone else bothered by these thoughts sometimes?

There is currently no definitive answer as of yet, but there are some hypotheses. First, note that the Big Bang Theory is generally accepted and has solid evidence, but it only covers what happened about 0.00000000000000000000000000000000001 seconds AFTER the initial event. It makes NO claims about what actually happened during or "before" (if there was such a thing) that first fraction of a second. The Big Bang Theory itself has been updated several times and is sometimes referred to as Inflationary Cosmology (or whatever they call it now).

Do some research on the Big Bounce and Quantum Loop Gravity for some of the current buzzwords. If I were you, though, I'd avoid bothering with String Theory, unless the LHC manages to provide evidence for it. As it stands, the various String Theories have exactly ZERO real evidence, so they aren't really "theories" at all.