The other day my son walked into the bathroom, pressed the first light switch, which is next to the fan switch, and used the toilet.  It took me back a second because when I saw him do it, I couldn’t quite believe it.  Before then—or before whatever moment he had started turning on the light by simply lifting his hand—he had always stepped on his stool, the one which blocks a side of the sink cabinet, and pressed both buttons under the dry towel, to turn on the fan and the light.  Until some moment in the last few days, the last couple weeks maybe, he was too short to reach the switch.