On day one (August 1st) I switched the camera to manual and proceeded to take my first self-portrait. The shutter took an inordinately long time to kick in. I figured this must be some strange feature of the camera when set to manual, and thought nothing more of it.
For the next 19 days (August 2nd through August 20th), I took photographs of myself in various poses, waiting patiently each time for the shutter to take its sweet time going off.
On day 21 (August 21st) I was fiddling around looking at the information on the display screen. It was only then that it dawned on me. I'd had the 12-second self-timer on the entire time...
Please note that in my self-portrait for day 21, I'm looking a tad sheepish.