Inferiority complexes can be useful Having a chip on one's shoulder is often seen as a defect or a failing. But I think it can be a great motivator, and a spur to action. Better than complacency, by a long way. I was reminded of its importance reading an interview with electronics retailer Julian Richer in a new book about entrepreneurs, The Branded Gentry, by Charles Vallance and David Hopper. Mr Richer is a brilliant retailer whom I saw in operation first-hand when we were briefly in business together. He is a fascinating character and says in the book that "a chip on his shoulder" at boarding school made him "more determined than ever" to succeed. Mr Richer's insecurity and hunger partly stemmed from "being a less wealthy pupil among a privileged school population." I know the feeling. When I was a teenager our family used to spend our summer holidays in a bungalow in the grounds of a Scottish castle owned by friends of my parents. They were much grander than us, and all their children went to the most elite schools: meanwhile, like my siblings, I attended a state school in a suburb of Slough, a deeply unglamorous town west of London that was the setting for the original series of The Office. It was hard not to develop something of an inferiority complex, although we were hardly deprived. Nevertheless, I could not wait to grow up, become independent and forge my own way in the world. A grievance can be a positive force, if employed constructively. Last week I taught a lesson in an inner-London academy to a class of 15-year-olds. It was a far more challenging task than the two speeches I had to deliver that day to corporate audiences. I spoke to the teenagers about going to work for themselves when they finish school, and set them the task of preparing a mini business plan. Of the 20 pupils, at least five had parents who were self-employed, running enterprises such as kebab shops or taxi companies. Almost all of them were the children of immigrants from modest backgrounds. I sensed some burning ambition in the classroom, and would put money on one or two becoming high achievers with their own businesses in the years to come. The whole career of one well-known boss was described once to me as "an act of revenge" against his previous partners. I instantly understood this. A thirst to prove contemporaries, critics and rivals wrong can act as a powerful driver. As the management thinker Peter Drucker wrote, "whenever something is being accomplished, it is being done, I have learned, by a monomaniac with a mission." Cornelius "Commodore" Vanderbilt, a robber-baron who built up an enormous fortune in the shipping and railroad industries in the 19th century, was famed for writing a letter to two former partners who had double-crossed him. "Gentlemen, You have undertaken to cheat me," he wrote. I won't sue you, for the law is too slow. I'll ruin you. A present-day avenging angel in the same mould is Tim Martin, the publican of JD Wetherspoon fame. He recently announced he had spent eight years pursuing litigation on behalf of his company against certain agents and landlords who had defrauded him. He has bankrupted several individuals and received large sums in settlement from others. Determination is generally a much more important asset for an entrepreneur than qualifications or connections. So many self-made individuals are dropouts from college it has become almost a rite of passage. Sara Blakely, the billionaire founder of Spanx, failed law school exams twice. So instead of becoming a lawyer, she learnt how to be tenacious in the face of rejection while selling fax machines and photocopiers by cold-calling. "I had my business card ripped up in my face probably about twice a week," she says. But she didn't give up - and discovered how to win customers and close a sale. Entrepreneurs are disrupters who tend not to fit the establishment mould. Many suffer from dyslexia or stammer, or were adopted, or experienced the early loss of a parent. They seek autonomy, and to show the world that they are neither lazy nor stupid, but a winner. They just prefer to do it on their terms. The writer runs Risk Capital Partners, a private equity firm, and is chairman of StartUp Britain. He is the author, most recently, of "Start it Up"