Just click the flag and watch as the normal distribution is formed!
How does this work? Well, imagine you picked a random number a load of times, and plotted them out. They would be evenly distributed. Well, what if you did the same, but instead, you plotted out a load of averages of random numbers. They would tend towards the middle. We see a similar thing in reality: There are lots of people who are average height, but the shorter or taller you get, the less people of the same size there'll be. The smooth curve at the end was made using a rolling average.
