Another element that makes the Big Bang even less intuitive is that it is a singularity in time as well as space. That means that there’s no point in asking what happened “before” the big bang, because there was no before. Time itself doesn’t exist beyond that point, so our usual ideas of cause and effect break down here.
The best analogy I’ve heard of it is that time is like distance north-south, and the Big Bang is the north pole. You can’t say what’s one metre north of the north pole, because the direction “north” doesn’t exist once you reach the pole.
If you’re used to living in an area that seems very flat, where North and South are well-defined and useful directions, the idea that they just stop existing at some point is very odd and seems nonsensical. However, once you know about the curvature of the earth and the shape of the globe, then this makes sense. In the same way, people who live in a part of the universe where time seems to be a constant find the idea of a singularity very odd.
