We've just passed a milestone: Twenty years ago, on January 3, 1972, Blue Chip Stamps (then an affiliate of Berkshire and later merged into it) bought control of See's Candy Shops, a West Coast manufacturer and retailer of boxed-chocolates. The nominal price that the sellers were asking - calculated on the 100% ownership we ultimately attained - was $40 million. But the company had $10 million of excess cash, and therefore the true offering price was $30 million. Charlie and I, not yet fully appreciative of the value of an economic franchise, looked at the company's mere $7 million of tangible net worth and said $25 million was as high as we would go (and we meant it). Fortunately, the sellers accepted our offer. The sales of trading stamps by Blue Chip thereafter declined from $102.5 million in 1972 to $1.2 million in 1991. But See's candy sales in the same period increased from $29 million to $196 million. Moreover, profits at See's grew even faster than sales, from $4.2 million pre-tax in 1972 to $42.4 million last year.

The friends with whom I sat on graduation day have been my friends for life. They are my children’s godparents, the people to whom I’ve been able to turn in times of trouble, people who have been kind enough not to sue me when I took their names for Death Eaters.

My country is a country of teachers. It is therefore a country of peace. We discuss our successes and failures in complete freedom. Because our country is a country of teachers, we closed the army camps, and our children go with books under their arms, not with rifles on their shoulders. We believe in dialogue, in agreement, in reaching a consensus. We reject violence. Because my country is a country of teachers, we believe in convincing our opponents, not defeating them. We prefer raising the fallen to crushing them, because we believe that no one possesses the absolute truth.

I did boxing because I needed to channel the pain. I did karate because I was being beaten up and I wanted to be able to defend myself.

I might have liked to have done it a couple of years later, but you'd be stupid to turn it down.

We were training 12 to 15 times a week, 50 weeks of the year. I think sometimes people see you compete at the Paralympics or other amazing places around the world and think that is what you do all the time. There is an element of that, but a lot of it is just really boring and repetitive. The vast majority of your time as an athlete is spent on the road or in the gym.

One thing that I did was race against the British men a lot and they used to push me round the road; they used to make my life really hard but then when I was racing against the best women in the world, I'd been through just about every experience you could imagine. I remember this one race – a half marathon – where my husband literally pushed me into every kerb he could find, he pushed me into every corner, you know, messed around and tried to drop me out the back of the pack. Then when you're in a race that really matters, if that happens, you've got the skills to deal with it… you need to have practised everything you possibly could in the lead up to it.

I love training. It's not just about the competing. I had an amount of natural talent – you need that to go so far – but, actually, what I had, I think, is an ability to make myself work hard, to do the things I didn't like doing, to do the things that I wasn't so good at.