Some of the most inspiring self-tracking projects.

The Quantified Self site has an apt, Socratic motto: "Self knowledge through numbers." (Though maybe it should deploy a hyphen in there.) It's where I go to learn from the most dedicated self-trackers, the people who are pushing this idea forward. Let's take a brief tour of some of my favorite videos from Q.S. meet-ups.

Seth Roberts, a professor of psychology, is in some ways a poster boy for the movement. He has the impish confidence of the handyman, and a kind of countercultural curiosity about how his mind works. In this talk, he discusses how he measured his brain function by timing his performance on a daily three-minute arithmetic exercise. He noticed an anomaly in the data where his scores suddenly became much better. What could be causing this unprecedented brain speed? His hunch was butter.

To test his hunch, Roberts increased his butter consumption by half a stick per day. His buttery brain was able to duplicate the results—he was 30 milliseconds faster. Listen for the shocked laughter in the audience. In the question-and-answer session, a doubter points out that though Roberts may be improving his brain function, he's also setting himself up for death by heart attack (which is known to slow down one's math abilities). Roberts' response gets at the essence of the Q.S. philosophy. The science that correlates diet with increased risk of heart attacks is not entirely proven and based on studying large numbers of people. His butter experiment is a study of one, and the results are completely clear to him.

Next up are Hulda and Josh Klein, who were faced with the task of moving from Seattle to Iceland. They made a list of their possessions and set about categorizing them in a smart way, emotionally. This was the list of categories:

I Love This Thing, and I Use It All the Time.

I Love This Thing, Because It's a Good Memory.

I Love the Way This Thing Looks, and I'm Going To Keep It.

This Is Useful, But It's Lacking Somehow.

This Is Useful, But I Don't Love It.

If the item fell into the first three categories, the couple would keep it. Otherwise, gone. Using this process, they discarded half of what they owned, put one-quarter in storage, and brought the remaining stuff with them. The lessons learned were not completely surprising, but they were tailor-made. Because cooking was important to them, they brought great chef knives but realized they couldn't care less about flatware. In general, they became much less afraid to throw stuff away. Partly because they had put an Eames chair in storage and then practically forgot they owned it.