To ask,"why is there something and not nothing" is like asking, "is the number 7 married ". Obviously "yes" is absurd. "No" is also absurd.The number 7 is not a bachelor ! The question itself is absurd!
There is no explanation for why there is something and not nothing. If there is an infinite regress of explanations (This is beacuse it was caused by this...ad infinitum) that is not an ultimate explanation . Imagine that we explain the earth's position by saying that it rests on an elephant and that elephant on....that does not explain why they are elephants and not (lets say) rocks. If the chain of explanations does have a original ( ultimate ) explanation ,that explanation (by definition ) does not have an explanation !!!!
Yes, that is weird!!!! More weird then the weirdest Twilight Zone! It took me a long time to accept the fact that reality is absurd.