How could there not have been something before the Big Bang?

Nature has over the years presented us with many physical situations where our intuition about how things 'ought' to behave has been shown to be absolutely false.

The list is actually quite long. So, as to how it is that the universe 'MAY' not have required something or some event 'before' the Big Bang to start the process, this may be just another example of our intuitions demanding a phenomenon that nature simply did not need to provide to get the job done.

In the quantum world...the world that the universe inhabited when it was less than a second old...many things work very differently. One of these is that time itself did not mean quite the same thing as it does to us in the world-at-large today.

Although we have no complete theory of the relevant physics, there are many indications from the mathematics that yield sound experimental results. Because of the strange way in which quantum physics and its laws operate, time itself may have ceased to have much meaning near the Big Bang event. This means that there was no 'time' as we know this concept 'before' the Big Bang. That being the case, the question of what happened before the Big Bang is now a question without any possible physical answer. The evolution of the universe has always been a process of transformation from one state to the next as the universe has expanded. At some point in this process, looking back at the Big Bang, we enter a state so removed from any that we now know, that even the laws that govern it become totally obscure to science itself. In the quantum world, we see things 'appearing' out of nothing all the time. The universe may have done the same thing. What this means to us may never be fully understood in an intuitive way.