Say you eat a casserole that’s so blended you can’t tell what the ingredients are, and love it. Then someone tells you that the casserole had some spinach-and incidentally, this is the first time you’ve had spinach, ever. Do you like spinach?

You can’t immediately tell, and the same is true of a lot of things in your everyday life, particularly when it comes to influences like your job or where you live. Day to day influences-weather, your health, hormones, or having a fight with your girlfriend-typically have a much bigger effect on your mood at the moment than anything long term. How do you isolate the effects of any individual source of emotion in your life?

Two years ago I was absolutely certain that I would want to go to grad school for a PhD in Math. Today I’m looking for a job in Finance, after realizing that what I liked about Math wasn’t what I would be doing in grad school.

So how did I choose what to do? Rather than try to gauge emotion, I look at energy. It’s easy to track what thoughts keep me awake and inspire me to action, vs. things that fill me with dread and make me exhausted. I love solving problems. I love reading lots of theory and seeing how it produces short, clever solutions to very general problems with broad-ranging applications-that’s what I enjoyed in Math. That’s what a lot of Math education is like. But most research is about very specific problems that may or may not have applications, and the number of people who read a given paper is very small. When I thought about it, it was clear that I get most excited by projects with far-reaching and measurable consequences. But the thought of doing work that almost no one reads exhausts me.

Similarly, being around my SO makes me excited and more alert. My friends noticed this before I even realized I had a crush on her.

Measuring energy is a major consideration you can use to decide where to work, live, and your general lifestyle. It’s a quick way to measure whether something makes you happier. How do you measure your happiness? What are some other indicators you can use?