It felt the strangest thing attending not so long ago the 50th anniversary of the year I graduated from Diocesan Boys School. I recognised some contemporaries immediately, though most them are three times the size they were when we were young. We shook hands and some of us had to ask who the other was. But there was no problem talking about the old days and it therefore felt very natural. I'm not an emotional person as such but I do think the friends you make at secondary school continue to be much better friends than those you meet in your working life. When you make a friend in secondary school there's no conflict of interest whereas in your working life there's competition. Going to DBS was not about getting good exam results so that made competition less keen. I remember in Form Seven we had to take our A levels at the University of Hong Kong. Waiting to go in, students from the other schools were revising whereas the DBS contingent was having a look around the gardens. I think it showed we were trained to be calm and confident. I came from a poor family. Dad had been a successful businessman before the war but his assets were confiscated by the Japanese and had to start all over again, so I was very lucky to go to DBS which was considered to be a school for the rich. Many children had not gone to school due to the Japanese occupation and those that were lucky enough were not taught in English. I didn't know the alphabet, let alone how to write my name in English. The entrance exam covered maths, English and Chinese and the only part I could do was the latter. On the first day of school I couldn't read the signs which were all in English. Each classroom had a picture and that's how I found my way back to it. But by the mid-term exams, I was 23rd out of 80 students. Science was my forte. I liked to know why things happened and had a logical mind. I wasn't good at memorising things. However, it was my geography teacher who I remember. He taught the subject in a way that you didn't have to study it. I just used knowledge and logic. What was memorable about DBS was that we weren't bookworms but we still got good results without much studying. I played sports that I could afford and didn't need expensive equipment for. I opted for football because you could buy one for a few cents. I'd wanted to do architecture but dad didn't know whether he could afford to pay for the five-year course. In addition, the qualification in Hong Kong was not recognised professionally. It was the headmaster of DBS who suggested I change to another subject so I could get a grant, provided I taught for a few years on graduating. In the end I majored in geography and geology at the University of Hong Kong then did my master's while being a teaching assistant. In the 50s the Hong Kong government was advertising for its first planners so I joined. It turned out to be a good choice. The city was examining a big overall plan and what I liked about town planning was that you learned a bit about everything and didn't specialise. Town planning is about organisation, statistics and architecture. People call us 'Jack of all trades' but in fact we're all-rounders. It took from 1964 to 1971 to draw up a plan for Hong Kong and based on that we created the New Towns we have today in parallel with the public housing programme. I'm now the chief executive of the Hong Kong Policy Resource Institute, a think tank and non-governmental organisation. Founded in 1996 we advise and offer ideas to the government. We don't ask for feedback nor do we expect it but we understand notice is taken of what we say. It's interesting how when we went back to school as part of the 50th anniversary it all looked very different. But all I had to do was close my eyes and I could feel where I was because the atmosphere still felt the same. Dr Peter Pun Kwok-shing is the chief executive of the Hong Kong Policy Research Institute and Hong Kong's former director of planning. He was talking to David Phair.