At some point in time, I forget when, my wife bought us electric toothbrushes.

Here is how the electric toothbrush works: The manual divides your mouth into four zones and when you turn on the toothbrush you are supposed to clean one zone for 30 seconds until the brush vibrates and you move to another zone until your 2 minutes are up and the motor stops.

One thing I quickly learned practicing this sleek mode of oral hygiene is that I have no internal sense of how long 30 seconds actually takes. Sometimes 30 seconds is barely enough time to touch all the zone’s teeth and sometimes by the end I feel like I’ve repeated the zone’s row over and over.

I often spend the 30 seconds harmonizing with the tone the motor emits. I took the toothbrush over to the piano one day and determined it plays in the key of C, although if you switch it into sensitive mode, it drops a half a step down to B. I pick different songs, but I’m never sure how many lines I can get in before I have to switch zones. (I’m reminded of how my wife used to measure the length of her commute by how many times she could play Calexico’s cover of “Alone Again Or” on repeat.)

If I can’t keep a sense of what it’s like to pass 30 seconds, how am I supposed to have a sense of a morning, a day, a week, a month, a year?

“A year is short,” writes someone who traveled nonstop for a year. I’m not so sure I believe her. This toothbrush has unloosened any confidence I have in what it takes to pass any length of time. The worst part is that I can’t go back again: my teeth just don’t feel clean anymore without it.