It all started when New York Times reporter Charles Duhigg couldn’t understand why he had trouble sticking with an exercise routine.

“I felt like I was a fairly successful, intelligent person, but then there were all these things I didn’t have all the control I wanted over–like making myself eat healthfully or exercising as much as I should have,” Duhigg says.

So like any good reporter, he started doing some research. “And I realized that we’re living in this golden age of understanding the neurology of how habit formation works, and why patterns emerge within our lives,” he says.

So he wrote a book about it: “The Power of Habit: Why We Do What We Do in Life and Business.” We sat down with Duhigg to talk about common habits in our financial lives–as well as how to deal with bad ones and create some good ones.

LearnVest: When most people think about their bad habits, they list one or two things, but according to your book, people actually have hundreds. Really?

Duhigg: “Yeah, a researcher found that 40% to 45% of what we do every day isn’t actually decision making, it’s habit. So a habit is a decision that you made at some point that you continue to act on.

“For example, backing your car out of the driveway is habit for most people. It’s actually a pretty complicated activity when you think about it. The first couple of times, people have to concentrate, monitor the mirrors, gauge the distance … it takes about a week, and then you can start doing it almost on autopilot. You can talk to your kids, fiddle with the radio. Our brain has this amazing ability to take repeated patterns–even complex ones–and make them into habits.”

If most habits are subconscious, how can people identify the bad ones that are crippling them financially?

“When it comes to bad habits, people know that they’re there. When it comes to finances, a huge part of it is just tracking data. It’s looking at when you’re exceeding your budget–and you’ll know pretty quickly when and how that’s happening, whether it’s going out to dinner too much or buying a coffee every day. Everyone knows what their bad habits are–the hard part is figuring out how to change them.”

So what’s the first step?

“The first thing you have to do is figure out what the cue is for that habit. Cues fall into five categories: