Up until I was 16 I attended a convent school and had quite a difficult time of it. Boarding school seemed like a lonely place and I felt as though I was missing out on the creature comforts of home. I lived in a shared room and had no private space - it was always difficult to get away from the crowd. If you wanted to have a bath, you even had to book a time slot.
The school was run by nuns, so there was a fast day every week. I remember talking to one of my oldest and dearest friends who attended the convent with me and we agreed that our most distinctive memory was constant hunger. When there was food, it was absolutely appalling.
There was very little to do - boredom and starvation are the two memories that stand out in my mind. The convent was in the middle of nowhere, which didn't help. The work was not of a particularly high standard and the sports facilities were a joke, which was a problem for me because I always enjoyed my sports.
Luckily, the school didn't go on past 16, so my parents decided to send me to another boarding school called Aldenham in Elstree, Hertfordshire, an all-boys' school that had recently started accepting girls into sixth form. After my negative experiences at the all-girls' convent school, my parents decided that sending me to an all-boys' school would be the perfect antidote.
At Aldenham, academia was important, but your personality and your ability to mix with people - to get on with the crowd - was equally important. The school was owned by a brewery, so we had our own pub, which was great fun. The school even offered wine tasting lessons, which gave it a kind of college atmosphere.
I had a housemaster there called Mr McAllister, who gave me more chances than he probably should have. He was rosy-cheeked and cheerful. My lasting memory of his wife was her tendency to roll her eyes at us for the latest antics that we had been dragged into her husband's office for.
Mr McAllister often caught us smoking out of the window. As punishment, he made us go for a run at 6am the following day - so of course we took the opportunity to go outside the school gates and have another cigarette. He showed a great deal of patience, and we are great friends to this day. I still find it hard to call him by his first name.
He was one of those wonderful people who really understood that we were growing up and that we all had different ideas of right and wrong. Fundamentally, he was raising us and trying to teach us the importance of friendship and respectability. He also gave us the most important thing you can give teenagers, which is trust. I think he knew we would abuse it, but he gave us the freedom to make choices.
Once in a while, he would arrange for companies to come to our school and give presentations and make us think about which businesses we could imagine working for. As a result, I was asked to join two companies. One was the London Broadcasting Company and one was Saatchi amp; Saatchi. I chose Saatchi amp; Saatchi purely because they offered us lovely chocolate biscuits. That really kick-started my career
Businesswoman Karren Brady is soon to become one of Alan Sugar's advisers on reality television show `The Apprentice'. She has just become vice- chairman of West Ham Football Club. She was speaking to Friederike Heine.