I had just turned sixteen when I accepted a job as a server at Coco’s Famous Hamburgers restaurant. The now defunct restaurant chain had a loyal following of customers who wanted not just delicious food, but also outstanding service. Unfortunately, I was a tremendously shy teenager, not necessarily a good attribute for someone who had to greet hundreds of hungry strangers as part of her job duties.

Needless to say, my foray into waitressing was rough. Once my arms and hands were shaking so bad from nerves that I inadvertently dropped four plates of famous hamburgers right into the laps of four ravenous guests. Once I slipped on a puddle of water and fell, with a large sundae in each hand, straight onto the hard floor in front of a waiting line of customers. Fortunately I was desperate enough for money so I could put gas into my 1973 Chevrolet Bel-Air that I persevered through my first few weeks, all while managing to avoid being fired.

Throughout the next three years, I learned many valuable lessons that I carried forward into my career and life. Decades later, I still benefit from the below lessons that taught me much more about myself and life in general than I ever imagined:

1. Practice makes perfect. At first, I admit I wasn’t a great server. In fact, I was pretty darn bad. I made mistakes, dropped plates, and delivered food to the wrong table. Yet through it all, there was one thing I knew for sure: I could do that job if I just focused on being better, one day at a time. So I did and then one day, everything just clicked. I delivered piping hot food to the right tables, cranked out delicious malts from the malt machine, and kept my footing even on the wettest of floors

2. Never give up. There were times, especially in the beginning, when giving up was an attractive option. Being a server is one of the hardest, least appreciated professions. Still, I persevered through the bad days, all while keeping my focus on the good days. I learned new ways of doing things, kept looking forward, and developed great friendships with my co-workers. There was one thing I knew for sure: Quitting wasn’t an option because I was transforming my weaknesses into strengths every day.

3. Failure is part of success. I’ll never forget the night that a foursome came into the restaurant. They had a plane to catch and were in a hurry. They all ordered fried chicken, a dish that took 40 minutes to cook. I notified them of the wait. What I didn’t realize is that I had inadvertently left the ticket in my pocket and hadn’t submitted it to the cook. An hour later, the customers were livid, late for their plane, and I was in trouble. From that point forward, I always double-checked my pocket to ensure I hadn’t forgotten to submit an order. As I navigated through that failure and many later failures, there was one thing I knew for sure: We all make mistakes. What is important is to learn from them.

4. There are more good people than bad in the world. Being a teenager comes with lots of insecurities. Although I waited on a few customers who were angry and rude, I waited on many more who were kind and thoughtful. One morning, I waited on two guests who were quiet yet respectful. I didn’t think I did anything extraordinary. Yet when the guests finished their meal, they left me—a pretty dorky teenager at the time—a generous tip along with a handwritten note that said, “They say that the eyes are the window to the soul. If that is true, then you must have a beautiful soul.” That note touched me so much that I still have it today. From that moment on, there was one thing I knew for sure: It only takes a minute to positively impact someone’s life with kind words or a thoughtful gesture.

5. A smile goes a long way. A smile is a powerful tool. As a server, I held that power every time I put on my uniform and showed up for work. We all have bad days where we want to throw in the towel and live on a deserted island. Still, it doesn’t seem fair to transfer that momentary unhappiness onto a random stranger, does it? Throughout all the hundreds of days that I greeted and helped strangers fill their empty stomachs, there was one thing I knew for sure: Smiling provided happiness not just for me, but for everyone who crossed my path.

In reflecting on our first jobs and every job we have held since then, it can be enlightening to think about what important lessons we learned from each experience. In our lifetimes, some professional roles will be challenging, others will be easy, and some may prompt us to question every decision we have ever made. But if we focus on taking the positive lessons with us—the kind that help us grow professionally and personally—then it allows us to move forward and become better employees, managers, or entrepreneurs in the future.

Vicky DeCoster is a Certified Life Coach based in Omaha, Nebraska, who specializes in helping her clients both locally and nationwide to move past obstacles, create a plan for happiness, and cross the bridge of transition to find a new and fulfilling direction in life. To read more about her and her practice, visit her at crossthebridgecoaching.com.