This is hidden brain.
I'm Shankar Vedantam.
We're going to start today with a little experiment.
I'll be the guinea pig.
I'm going to open the stopwatch app on my phone.
I'll hit start and count off 5 seconds while looking at the phone.
12345.
Okay, let me do that again.
12345.
Okay, now I'm going to hit start and count off 5 seconds without looking at the phone.
12345.
It was 5.43 seconds.
Let's do it again.
12345.
Much better.
5.2 seconds last time.
12345.
5.59 seconds.
The errors I made seem trivial, but it turns out they are not.
Multiply the small mistakes I made in milliseconds over all the countless decisions I make every day, and you can end up with a serious problem.