What did I learn from editing a national newspaper? Don't believe what people tell you

Is there a doctor in the house? Well, yes, actually.

Last week I was accorded the honour of being awarded an honorary doctorate by the University of Ulster. They made me a doctor of letters, which doesn't mean that I am now qualified to be a postman, but does confer on me a number of responsibilities, the most immediately pressing of which was explained to me at a black tie dinner the night before the graduation ceremony.

I was told - several times, in fact - to make my speech on behalf of all those who were to receive honours short and sweet. Particularly short. Around five minutes. No more than seven minutes. It will come at the end of a long ceremony, so the audience may be a little restless. The auditorium has very little air conditioning and everyone will be boiling hot. I can't say I wasn't warned, and I took my guidance seriously.

Up to that point, I had thought that my most difficult task would be to get the name of the city that hosted me right. I asked one of my colleagues. "Which is the politically correct version? Derry or Londonderry?" "Neither," she said. "There is no right or wrong way". Religion alone dictates which name you prefer, and to avoid opening up age-old wounds, various compromises are put forward. In news reports, the BBC alternates between one and the other, and, as far as the 2013 City of Culture is concerned, we know it as Derry/Londonerry. (The forward slash in this moniker has led some to refer to it as "Stroke City").

I settled on referring to it in my speech as "this great city". But protocol and brevity were nothing compared with my next imprecation, which was that I must impart a serious piece of wisdom, some knowledge derived from my years of experience, that the students could take away and reflect on in years to come. Blimey. The entire audience of 2,000 people would be feeling like that they'd been held captive, fully clothed in a state-sponsored sauna, desperate to go out and celebrate, and I had five minutes to give the younger ones some advice they'd remember for the rest of their lives. No pressure, then.

I decided to give a simple message, the somewhat dubious benefit of having edited a national newspaper for some years. Don't believe what people tell you. Always challenge the official version of events. Ask the awkward question, even if it makes you unpopular. I related this specifically to events around the Iraq war. At the time, I was editor of The Independent and we irritated the government by contesting the basis on which the country was taken to war. Tony Blair called us a "feral beast". The point was to illustrate the value in searching for the truth.

At the risk of sounding like Methuselah, I have become increasingly dismayed by the lack of curiosity exhibited by today's youngsters, whose ideology seems to be driven more by consumer preference than political conviction. Anyway, I did my five minutes, the pools of sweat were mopped up, and afterwards one of my fellow graduates collared me. "I liked your speech," he said, "but I didn't believe a word of it."