While working at a bank many years ago, I approved a $10,000 fraudulent transaction. When the FBI showed me pictures of the man who had pulled a fast one on me, I didn’t even recognize him. In fact, the whole situation was kind of a blur. At some point, they pulled the footage from the branch security cameras and, as I flipped through photos of myself smiling and giving what appeared to be excellent customer service to a man on the FBI’s watch list, I could hardly believe my naivety.

Unbelievably, I wasn’t fired. Though it would have been completely justified. My boss really stepped up for me. Not normally the sympathetic type, I think he was just as blown away by the situation as I was.

Clearly, that wasn’t a shining moment in my career. In fact, I’d venture to say it was the biggest and most devastating mistake I’ve made at any point in my professional life. Thankfully, I don’t believe in failure. So I see this as a critically important lesson in judgment.

To help you avoid such painful lessons, I thought I’d share the top 5 things I learned from this experience.

1. Don’t Zone Out

The most inexcusable part about my “situation” (as we will now refer to it) was that I didn’t even remember my thought process. I couldn’t justify my actions. Why? Because I was “in the zone”. Or rather, I was zoned out. I was doing my thing, the monotonous daily tasks I had come to take for granted. My brain was on auto-pilot. I ran hundreds of transactions a day. At some point, it only makes sense that I’d stop paying close attention to each one.

Good judgment is an active process. Engage the brain. If you feel yourself falling into a mindless routine, shake it up. Start working with the opposite hand or move the items you use most frequently. Showing strong judgment doesn’t mean you won’t ever make mistakes, but when you do, you should have a clear understanding (and recollection) of what thought process led you to that conclusion.

2. Slow Down

The truth is, I was probably competing with the other tellers to see who could move through customers the fastest. Man, I hate admitting this. But that was a common occurrence. I was a manager so running a teller drawer wasn’t my favorite thing to do. I only jumped up to help out when the line was out of control. And my presence always forced the other tellers to pick up the pace. We made it a game as a way to relieve the tension. That backfired.

Never sacrifice quality for speed. It’s so tempting, especially when impatient customers are right in front of you. But breathe deep and take slow, methodical action. Good judgment requires time. Give yourself a minute to think about what you’re doing. Rushed decisions are never as defensible as those made with measured, deliberate consideration.

3. Multi-Tasking Is Dangerous

You guessed it. I was multi-tasking. It might not seem like it at first, but my attention was in fact divided. I was running a transaction while chatting it up with a customer. Now, I’m not saying I should have ignored the man in front of me. But there’s a time to shut up and focus, which I never did. I was more concerned with being friendly. I probably was trying to upsell him to an investment product. I definitely wasn’t giving the most important task in front of me the attention it deserved.

I’ve written before about the dangers of multi-tasking so I won’t rehash my point-of-view here. Just remember: Good judgment requires full focus. Give it less and you’ll get less.

4. Stress Manipulates

It’s only been in the last few years that I’ve learned how to appropriately manage my stress. Before that, I truly let it run wild. Stress has a way of manipulating your thoughts. Scientifically, it can actually alter your brain chemistry. Stress can physically change the way you see the world and how you react to it. If you’re under severe stress, you can pretty much guarantee that your judgment will suffer. Get it under control now or pay later.

5. People Aren’t All As Nice As You

This is a hard lesson to learn. I worked at the bank right after college and, until that point, I didn’t really understand just how much “bad stuff” happened each day out in the big world. Don’t get me wrong—I wasn’t an idiot. But I always thought I could SEE danger. And I trusted my gut. So I figured danger would either jump out with a neon sign over its head or I’d instinctively just know. Turns out, danger hides in all kinds of charming, fun, easy-to-talk-to places. Danger lives inside the most unsuspecting people and moments.

Good judgment means you’re willing to see what’s really there, even when it’s hard. You’re willing to look beneath the surface and confront the reality—that people aren’t always good and truthful. You may be a target. You may be the person who looks easily swayed or distracted, the one whose judgment looks questionable. Don’t let them get away with it. Show them that your judgment is sharp and nothing gets by you.

I wonder what it would have been like if I had followed these tips on that fateful day. Would I have stopped the man? Would I have notified the police, saved the bank thousands of dollars, and possibly even played a central role in bringing down the fraud ring this man was a part of? Who knows? It’ll always be a question for me.