It seems like his Dad is wealthy so he probably learned a bit from him about the business side.
In his book, he was quite critical of his dad. He related how he was a secondary school dropout, had little aptitude for sales and was often getting sacked from his jobs. In contrast, his mum was the one who stepped up and took control of the family's finances by getting a job. This is a revealing passage from The Reluctant Apostate:
As far as higher education was concerned, Mum and Dad were actually quite progressive and open-minded in comparison to most Witness parents. I think this was due, at least in part, to the fact that both of them had experienced quite austere childhoods. Neither of them came from wealthy or privileged backgrounds. Both were raised to view financial security as something hard to attain and not to be taken for granted. It was also around this period that Dad seemed to start getting fired from various jobs as a sales rep with increasing regularity. He had flunked school as a child due to his own problems with bullying, which he attributed to his dyslexia, and work as a salesman suited his skills and personality perfectly. Dad is a larger than life character; a talkative man with a good sense of humor and a gift for retaining information that most would consider useless. Even so, when it came to selling things, he did have his shortcomings. Mum once told me of an occasion when his boss sent him for an appraisal of his sales techniques. The conclusion? Apparently “he could talk anyone into buying something, but then talk them straight back out of it.” The occasions when Dad would come home and tell us he had been fired felt like a bomb going off in our family, leaving us all in shock. Mum took it especially hard, since she was the one running the household accounts and paying the bills. She felt the strain more than any of us. When things got especially bad, Mum found work as a painter/decorator—a job she had a natural aptitude for due to her background as an art student. Her artistic streak and craftsmanship also enabled her to make some extra money from the occasional furniture restoration job. However, Mum suffered from severe migraines that were easily triggered by the fumes emanating from the paints and chemicals she used. Never one to give up so easily, Mum managed to find a less hazardous job as a part-time nanny for a local wealthy family while still doing the odd decorating jobs here and there to make ends meet. I will always admire her resourcefulness and willingness to do her part in keeping food on the table. Mum was entirely selfless in putting the family’s needs first. If Hannah and I needed clothes, she would not hesitate to go without buying any for herself to make sure we were presentable. Even in our bleakest periods, I cannot bring myself to think of my family as poor. I have seen true poverty, so I could never frame my childhood experience in that context. Despite many setbacks, Mum and Dad did very well at providing a comfortable, happy environment for Hannah and I to grow up in. We had all the usual gadgets and appliances. We lived in a nice house in a quiet neighborhood with a big garden. We had two cars in the driveway (our own car, and Dad’s company car when he was in work). We managed a holiday each year even if it was only a camping trip to the Welsh coast. [33] Out of the dozen-or-so young families in our congregation, probably ours was among the better off financially. Nevertheless, money was certainly never taken for granted in our home, and I think the challenges faced by Mum and Dad gave them a more pragmatic approach to college education than most Witness parents.