I finally found it. I was screwing around with the mouse wheel of my Logitech MX 700 mouse. On the left of it, I found that there’s some dirt. I scrubbed it off. It’s gone.

I remember doing that for mechanical mouses. Turning the little piece on the bottom, taking out the ball (and feel its weight), and then sticking a finger inside to scrape the dirt off the 3 rollers. That kept me awake all day. I missed that now that I use something so technologically advanced. It just feels so great to clean something and make it work, especially when the dirt comes off in huge, hard pieces that you can pile up.

I wish I could do that with optical mice.