I am a runner. Last October, there was a marathon here in Beijing. I didn't participate this time, but friends told me that the run wasn't prepared too well. The organizers had only arranged about three hours' worth of food and water supplies. Most people don't finish within three hours, however. Too bad for them - or so it seemed. In fact, however, even those finishing last were perfectly taken care of, particularly during the fourth and fifth hour when demand is highest.

Isolation means a lack of growth. I grew up in China at a time when the country was completely isolated. That era is over.

On the one hand the world is getting more integrated and we should not dismiss social values as "Western" when they are actually modern values. On the other hand, individual countries have their own history and their own evolution. Trade unions, for example, don't play the same role in China as they do in Europe or the US.

Chinese no longer crave so much for food and accommodation, but they do crave democracy. I stand by that. I don't know which model China will follow.

I firmly believe that digitalization has only just begun in China. In addition to the taxi, transport, shopping and hotel businesses, many other industries will follow: education, health care, administration, even the legal branch - everything, really. There is still a lot of opportunity in China for the inventive and ambitious ones.

When we started out, we didn't really think that the era of great opportunity would end one day. We were much too busy developing our companies. But in today's China you can build a city, even a mega-city like Beijing or Shanghai, within 10 or 15 years. And then you are done. So in real estate development, the Gründerzeit is over. But that is not the case in other sectors.

I'm afraid what we are building today will not have the same impact and sustainability of the architecture of a 100, 500 or 1,000 years ago. The buildings of those days were miracles. We don't perform such miracles today. So we should be a little more modest. For my part, I'll be glad to show one of my buildings one day to my grandchildren and say: I'm proud of that.