Imagine two different people on the same mid-January day.

One lives in California. He walks outside in shorts and a t-shirt. The warm sun beams down on his face. He puts on his sunglasses, unlocks his car, and turns the AC on full blast.

One lives in New York. He walks outside in a heavy jacket. He grimaces as the cold wind hits his uncovered face. He opens the trunk of his car, takes out a brush, and starts cleaning the snow and ice off his windshield.

Which one do you assume is happier?

You just picked one in your mind. And I probably would have picked the same. Right up until I lived both.

Yes, the truth is the two people are both me, just one year apart.

And our assumptions about their relative happiness reveal an important cognitive trap everyone needs to understand.

In 1998, two researchers ​asked a version of this exact question​ to nearly 2,000 people.

Daniel Kahneman, the psychologist who would later win the Nobel Prize, and David Schkade were interested in understanding the impact of climate on happiness and our ability to accurately predict the happiness of others living in a different climate.

The participants were undergraduate students at either Midwest schools (Michigan and Ohio State) or California schools (UCLA and UC Irvine).

They were given a survey that was either:

1. A self-evaluation that asked participants to evaluate their own personal satisfaction across several dimensions, including specific aspects of life and environment.
2. A target evaluation that asked participants to predict the satisfaction of another individual across these same dimensions. Midwest students predicted the responses for a California student, while California students predicted the responses for a Midwest student. A control group predicted the responses for students within their own region.

The results were fascinating:

There was no statistical difference in self-reported life satisfaction of the students across the two regions. California students and Midwest students were equally happy on a self-reported basis.

But...

Both Midwesterners and Californians predicted that the Californians were much happier.

The researchers reasoned that when evaluating their own lives, students were able to consider the full picture of everything, but when evaluating (and comparing to) others, they were only basing their judgment on the most visible factor (the weather).

They called it the focusing illusion:

It's a cognitive bias where people overemphasize the importance of a specific, visible factor when estimating the overall happiness of an individual or group.

In other words, when we look at and compare ourselves to others, we obsess over the narrow, easily-visible factors of their lives.

Daniel Kahneman would later famously summarize:

"Nothing in life is as important as you think it is, while you are thinking about it."

And that focusing illusion extends beyond others and into your own life.

In a ​2003 study​, researchers found that college students systematically misjudged how much their future happiness would be dictated by a random housing draw. Despite acknowledging that social features of housing were the most important thing when predicting their future happiness, they dramatically overestimated the impact of the visible physical features of their housing.

They predicted that they would be unhappy if they got a "bad draw" (as defined by poor location, attractiveness, room size, etc.).

But as it turned out, their actual day-to-day happiness was largely determined by the social features (roommates, sense of community, etc.).

Across the twelve housing options, the visible physical features varied significantly, while the unseen social features varied little. So, they judged on what differed, not what mattered.

Both studies point to the same general trap:

Whether you're making decisions in your own life, or comparing to someone else's, you focus on what you can see. But what you can see is almost never what matters.

This means that comparison traps are often most damning with the people you can see the least of.

It's why the stranger's feed bothers you more than the neighbor's. Or why the glowing career updates of the person you haven't seen since college hit you harder than your colleague's.

It also means that when making decisions for your own future, you often fail to take into account the bigger picture of how you'll thrive.

It's why you move for a lower tax rate and ignore the fact that you don't know anyone in that new location. It's why you jump to the new company for the slight pay bump but forget about the mentorship and senior support at your current job.

And here's the harsh truth in all of it:

The unseen variables aren't always unseen.

The Midwesterners knew about California traffic, cost of living, wildfires, and earthquake risk. The college students knew about the importance of social life.

It was an attention problem, more than a vision problem.

Fortunately, attention is a choice. You can choose to focus your attention on the things that matter. The things you truly care about.

The question to ask is simple. I call it my Tuesday Test:

What would an average Tuesday feel like?

Before you unfavorably compare yourself to someone else, or before you make a life decision based on a prediction of your future, ask that question.

What would an average Tuesday feel like for that person I'm trying to compare myself to? Do I really want that whole life, or just that one feature I was obsessing over?

What would an average Tuesday feel like in this future I'm envisioning for myself? Do I want that day, or am I chasing the wrong thing?

That question helped me change my life. Because on the surface, the idea of leaving warm, sunny Northern California to move to the frozen Northeast seemed like a bad trade.

But despite the colder January, the average Tuesday involved seeing my son play with both sets of grandparents, a sauna session with my dad, and a community that felt like home.

The guy scraping ice off his windshield is the happier one. The ice just has nothing to do with it.

Stop comparing Januaries. Start comparing Tuesdays.