One of the most common questions I get from young people is “How do I know what I want to do with my life?” By which they generally mean “What job should I take?” or “What career should I have?”. And that’s a reasonable question, especially given how important work is to happiness.

My answer, unsurprisingly, is fairly psych based. And honestly, it is a pretty direct reference to one of my favorite books, the highly underrated Strangers to Ourselves by social psychologist Tim Wilson. One of Wilson’s key points is that trying to logic our way to what we want or feel is incredibly hard, because we often don’t have full insight in our unconscious. Instead, Wilson argues that we should look at our behaviors – what we do is, in a very real way, what we feel and think.

My favorite example is a friend of mine from college who always insisted that he liked Caucasian blonde girls, of the Baywatch variety. And yet in my many years of knowing him, I’ve never seen him date anyone but brunette Asians. Why? Because in reality, that’s what he likes: his true preferences are expressed over long period of choice.

Now you could argue that it is really just that brunette Asians are the ones who want to date him, and that’s actually why I love this example. Many people look at their current job as reflective of what they could get, rather than their actual preferences. And that may indeed be true. So go a layer deeper.

The way I always phrase the advice is this: try to think of a project at work where it felt like the time flew by. If you have trouble concentrating on a task, it is often because you don’t like it. But if you are in love with something, you can often find yourself doing it for long, uninterrupted periods.

For me, I give the example of data analysis. I can spend a good six hours wallowing about in a rich data set, look up, and realize that I really should eat, go to the bathroom, and blink – I’m that deeply into it. So if you look for moments when it feels like time flies by, you can then look for careers and jobs that have that as a central responsibility. Astronauts have written extensively about how they took essentially awful jobs in order to get to space (and lied on every psych exam), because space was their bliss.

Another trick is to look at where you are willing to spend your cognitive resources more broadly. For example, I’m willing to spend incredibly long amounts of time on planes in order to go and talk with people, particularly young people, about how to use psych to design a better world. So when I look for a job, I make sure that is a key component – that I am willing to sacrifice for it tells me how important it is for me.

And note that I didn’t just sit back and think about theoretical sacrifice. I’m looking at my actual behavior: what I am actually willing to spend my cognitive resources on. Trying to logic your way into your passions only works if logic is your passion. Look at where you spend your time, where you are happiest, and where you can work for a long time without feeling burdened by it. Then look for jobs that have those characteristics.

Side note: Adam Grant (who is a good dude) just basically gave a version of my TED Talk at Davos. Love that the “work worth doing” idea is spreading – maybe I should finally get the tattoo. Opinions?