This blog was written by our CEO, Jon Shalowitz, and first appeared on medium.com

I had my first retail job when I was just 13.

I was living in a sleepy suburb of Washington, D.C. that didn’t have many businesses at the time (now it’s a booming city of its own). But we did have a mom & pop toy store called Lowen’s. I didn’t know anything about sales, but like any kid I loved toys, so I kept bugging the manager each and every week until he finally agreed to take me on for the summer.

With a flexible attitude and hard work, I quickly proved I could handle whatever they threw at me, from working behind the scenes in the stockroom to eventually assembling bikes. But my favorite part was helping customers — many of whom were friends and neighbors — find the perfect toy. I learned a lot about customer service, sales, and even empathy at that job that shaped my professional path.

Of course, a mom & pop toy store is a far cry from a major tech company, but those early lessons were invaluable in getting me where I am today.

Here are the four essential customer service lessons you need to know — regardless of what industry you’re in.

1. Know your product.

When you work for a company that sells a product (read: every company) it’s critical that you understand what that product is, how it’s used, and how customers are most likely to find it.

At the toy store, a big portion of my job was stocking. When you’re a customer, everything looks so seamless and simple — you browse the neatly arranged shelves and eventually find exactly what you’re looking for. But in the stockroom, I was shocked by how disorganized and overwhelming it was behind the scenes.

I saw the massive amount of stuff that came in each day that had to eventually make its way onto the shelves. I had to inventory everything, from model airplanes and puzzles to stuffed animals. There was no automated system, so I had to go out and see how much we had on the shelf and restock if needed.

My experience in the stockroom showed me the importance of not only knowing the product but also product placement and merchandising. When you’re new to customer service, like I was, you’ve got to learn how and where to place items in the store to catch a customer’s eye.

If you want to keep your customers happy, there’s nothing quite like a hands-on experience with the product you’re selling.

2. Get used to talking to customers.

One day the toy store was short-staffed and my manager asked me to leave the stockroom and go out to help customers. I was stunned, as I had no sales training. I was just a kid, after all.

But I was also excited about the opportunity, so I went with it. I was 13, I had no ego, and I didn’t really have anything to lose. While intimidating, sales wasn’t quite as scary as I thought it would be. Mostly, I found it was really exciting to talk to customers and help them find that perfect gift.

This is a must for anyone working at a company. Whether you’re working in product management, finance or engineering, you have to get experience talking to customers about the product you’re trying to sell.

After all, there is no better perspective than ‘seeing’ your product from your customers’ eyes.

3. Remember that customers don’t always know what they want.

There are two ways to sell.

There’s basic selling, which is asking customers what they want and giving it to them. And then there’s giving customers what they don’t know they want…yet.

With years of experience, I’ve learned that the second kind is where the creativity happens because a lot of customers don’t even know what they want — especially when they’re buying something for someone else, which was often the case at the toy store. For example, I worked with parents who were buying things for their children, or their children’s friends. And in many ways, I was a real-time recommendation engine (like my company today). I talked to each customer about what they wanted, and what the kid was like, and I’d recommend things and gauge their reactions.

I had to empathize and visualize the person who would ultimately receive the present.

As a salesperson, there is a real personal satisfaction and rush when you watch a customer’s face light up when you’ve found the product they know is right.

No matter where you end up in your professional life, it will benefit you to imagine your customers going through their day and thinking about how to make it easier for them.

That’s what good selling is all about.

4. Visualize how the customer is going to use the product.

After I proved myself capable in the stockroom and on the floor, the toy store had me assemble bikes.

These weren’t road bikes, but kid bikes with training wheels. But they were surprisingly complex, and I didn’t have any power tools — just tiny wrenches. It took me about an hour to assemble just one. There were times when we were completely slammed because we’d sell three or four of them in a short period of time and I’d really have to hustle.

On one such day, I found myself falling behind, so I tried to cut corners to speed things up. But as I was rolling out the bike to present to a little girl and her parents, I noticed one wheel was wobbly. I felt horrible.

I was upfront about my mistake and asked if they could come back the next day so I could fix it. They weren’t happy, and neither was my manager. But I wouldn’t have been able to live with myself if the girl had gotten into an accident because I was careless. So I stayed late that night, pulled it apart, and reassembled it so the wheel was secure.

It was the right thing to do, and my manager appreciated that I spoke up sooner rather than later.

All businesspeople should visualize the person who will eventually use the product. I still conjure up that image of that little girl and remember that the product needs to be safe and ready to use. If only more companies did this, many of the ills that we face as a global society would go away.

Some of the best salespeople I have worked with often don’t come from a formal sales background or with formal sales training. What they do have in common is that these people all cite an early experience in sales as providing them with the tools for professional success.

To achieve your business potential, you may need look no further than your past.