My father was not a consultant, but he taught me more about consulting than anyone else.

Dad worked in a variety of occupations throughout his life: tree surgeon, barber, cab driver, Russian linguist for NSA, and auto parts store manager, among others. During his tenure in the last mentioned activity, he found an opportunity to teach me the art of business.

When I was 12 years old, Dad encouraged me to take on a paper route. Having run a paper route himself as a boy, he advised me on how to run my nascent business. For getting new customers he suggested, “Order an extra paper from time to time, then give it away to someone who isn’t on your route.” He told me to concentrate on providing great service — never be late, always put the paper inside the screen door, and smile when you talk (he’d already trained me to say “sir” and “ma’am”). All my customers loved me, and I never had a problem collecting my fee.

But delivering papers was still solitary work for the most part. Because I was painfully introverted, Dad worried that I might have trouble making it in the real world. So when I was 15 he offered to pay me out of his wages to help out at the auto parts store he managed. After I turned 16 and thus qualified for a work permit, he convinced the owners of the store to hire me for minimum wage. This job put me in front of the public for hours every day — a public composed of people with problems, people who expected me to solve them. It was the perfect crucible for forging a businessman.

Here are some of the lessons Dad taught me as we worked together:

The customer isn’t always right, but ultimately you must give them what they want within the limits of your business relationship — or you won’t have a business relationship for long. You can and should advise them to the best of your understanding, but sometimes people have to learn for themselves that you were right all along.

When you’re wrong, admit it. It’s often a hard thing to do, especially if you’re suffering from the Impostor Syndrome and are therefore trying to convince yourself and others that you know what you’re doing. But the choice is clear: you can either deny your fault and lose a customer, or fess up and probably win one for life — especially if you offer to make it up to them somehow.

Every job can become an art. Respect your skills and hone them. Find better ways to do each task. I was in love with the car that Dad had given me when I turned 16, even though it was old and nearly worn out. So Dad suggested that during the slow periods at work, I should look up each and every part for that car. The idea delighted me, being a natural collector of information. I dedicated a notebook to the project. I visited catalogs I never knew existed. I learned so much, not only about my car, but about cars in general and how to figure out exactly what part each car required (this was back in the days before the VIN number unlocked everything). It wasn’t long before I gained the reputation of being almost as good a parts man as my Dad.

The most important component of a business relationship is trust. Friendship helps to build trust. It’s hard for people to trust you if you confine the relationship strictly to business matters. That doesn’t mean that you need to get involved in their personal life, but take the time to converse with them on other subjects that interest them. Joke around a little. Be a fellow human.

Know how to set limits without being a jerk. Even though we always try to give the customer what they want, some customers will try to push it too far. When it gets to the point where the essential business proposition (fair exchange) isn’t working, then you have to call a halt. But you can do so in a firm but calm and friendly manner: “I’m really sorry, but we can’t do that.” Once you’ve established that boundary, then look at the problem from the customer’s perspective, and see if you can come up with another way to meet their real need.

Don’t sacrifice long-term goals for short-term gain. This principle eventually led me to better opportunities, and away from working with my Dad. I went to college, where I first learned about computers. I developed my skills while working for others, then became an independent consultant. Along the way, a number of superb mentors have blessed my growth in the art of software development. But nobody has taught me more about running a business than I learned from dear old Dad.