Think about the last time you were at a restaurant. Great meal, enjoyable conversation, a few drinks and a fun night out. You’re enjoying the company, the time away from work, the background noise and the conversation.

Then the check comes. Confusion ensues.

Even though we can print organs, fly to space, create self-driving cars and eradicate smallpox, for some reason splitting a check among 3 or more people still remains nearly impossible.

Plenty of times I’ve wondered why this is. Splitting a check should be relatively straightforward – each person takes what they ordered, adds a 20-25% tip and pays that.

The act of splitting a check is so complex because it involves other people. When emotions get involved in otherwise rational decisions, they quickly make a simple situation more complex. They force new decisions on you. Do I want to be a nice guy and pick up the check? Can I get away with having the bill split evenly, even though I ordered the most expensive item on the menu? Can I under-tip and hope nobody notices?

These internal questions add layers of emotional complexity to what is otherwise a basic equation. Your answers to these questions can depend on how you’re feeling at the time, whether or not you recently got paid, how your relationship with your girlfriend is, and so on.

Emotional complexity is everywhere: hiring, firing, working with others… The ability to successfully navigate this complexity can literally make or break your career. Rationally, you hire someone to do a certain job. You set goals, benchmarks and metrics to help judge whether or not someone is meeting expectations and doing a good job. Again, rationally, if they aren’t hitting the goals you’ve established, you should part ways. No hard feelings.

We all know this isn’t how it actually works. I’ve been fired, seen others fired, and recently been the one actually doing the firing. For those that haven’t done it yet: it sucks.

I’ve been laid off once and fired twice. Once because the company was going through some hard times, another time because I took off 18 days in a row (sorry LA Fitness), and another because I underestimated how much work 20 hours a week was when you’re trying to get a company off the ground.

Being fired was not fun, to say the least. As the one being fired, I didn’t think rationally about how I was late on a few projects, or how my last project wasn’t exactly my best work. My immediate thought was that it was personal – they didn’t like me, I had somehow offended the wrong person, I would never be successful in a career, etc. My emotions got involved and made the firing more painful and personal than it should have been. It removed the possibility of treating it as a learning experience, and instead made the event a blow to my self-confidence.

As hard as they can be, such situations can also be an advantage. In the case of getting fired, I was able to get some clarity (once I got over the emotional aspect) about what I wanted to learn and what I wanted to do with my life.

This can apply to other situations, like finding a job. Rationally, a hiring manager *should* go with the most qualified candidate, but will often hire someone they know and like. What this means for the “unqualified” candidate – someone without the perfect resume or the right connections – is that you can get a job by introducing emotion to what would otherwise be a purely rational choice. Take them to coffee, do informational interviews, keep in touch via email, etc. Build a relationship instead of a resume to turn a rational decision into one based largely on emotion.

There’s nothing incredibly insightful here that others far smarter haven’t talked about. I guess my main point is that I’m constantly surprised at how many decisions in the world are driven by emotions and relationships instead of the intelligent, rational adult mind that I thought dictated most things. Envy, greed, fear of missing out, kindness and reciprocity are all very human emotions that have a real impact on how the world works. And I didn’t realize that until I started thinking about how to split a check.