There is something awesome and bizarre about large crowds of people. No other species behaves like this. Whether it's wildebeest, schools of fish, or ants, when members of a species assemble in large groups, it is for a common purpose. It's to carry out a function, to promote the grater good, to ensure survival.
But here we are, flowing along a busy street crammed together, competing for space, all going about our business, often with competing and contrasting desires... Will we survive?