John Hagel briefly discusses why he thinks urban life is more advantageous to a rural one in his speech on cities.
Hagel begins first by talking about the idea of human beings being closer than ever before. With modern technology it no longer matters where you live, you can communicate to anyone in the world. Paradoxically at the same time, we as a society are becoming more urbanized at a faster rate than ever before. The reason behind this Hagel suggests, is an intuitive sense that by moving to the city we will learn more -- and faster. In cities we are surrounded by a lot more people, particularly those who are more like-minded and able to discuss with us things we are interested in. In addition to that, there is a greater opportunity for random encounters with people who may aid us in our quest for knowledge.
Hagel points out in his speech on cities that there are of course many other factors that push people into moving to cities, but he cites that our desire to want to learn faster to be a factor.