I've seen people do this with the Clear button on calculators. They press it repeatedly, presumably in the belief that extra presses make it "really cancel". Something to do with their mental model of the calculator's internal state?
I used to do this. It's because of the confusing presence of the AC button. The UI has made clear to you that there are multiple levels of cancellation, one can in fact "really cancel." We know full well that there is some overcomplex internal state to the device, and rather than reading the manual for a calculator (honestly) we hammer the cancel button a few times, just to make sure.
A quick search reveals that some calculators have an AC button (clear everything) and a C button (clear last entry), while others have C (clear everything) and CE (clear last entry). Definitely confusing.
Some calculators do function this way. Pressing the clear button once clears the current screen but doesn't clear the equation. Pressing twice clears everything.
