Our brains likes to be in control and cannot comprehend big numbers. So if there is a large number say 1 million we like to think this is a manageable amount. Big numbers are more accurately imagined as infinity rather than finite group.

When you stumble upon infinite, or stuff like internet that is closer for our imagination to infinite than finite we start applying mental models from the finite world. i.e. I was looking at awwwards website and was surprised how many new great websites are there. Why is this surprising? Why do you think you understand 7billion? The number of people>designers&coders may be of the number that could be so big that you cannot even comprehend?