How big is seven billion people?
There are nearly 7 billion people on Earth. How much is that? Imagine that you want to shake one of their hands, to all of them, and that it takes one second to shake one hand. Then you would need more than 220 years to shake all these hands… Without sleeping nor eating!
By comparison, there are about 3 billion words on Wikipedia English. Reading of them would would take you around 30 years only!
This last comparison raises an interesting point. If we consider that all human knowledge is exposed in Wikipedia, this would mean that an extremely bright mind could potentially memorize most of contemporary human knowledge in a human lifetime. Obviously this only holds if the person is very bright and can understand complex reasoning (for example philosophical or scientific) as fast as he/she reads trivial text…