I do it when I urinate. Safety above all else.
I first realized years ago that I'd efficiently imbibed the theory of Rule 3 when I picked up the Windex spray bottle and my finger was automatically "in register."
"Therefore, since the world has still... Much good, but much less good than ill,
And while the sun and moon endure, Luck's a chance, but trouble's sure,
I'd face it as a wise man would, And train for ill and not for good." -- A.E. Housman
I catch myself doing that whenever I grab anything, be it a drill or the weight plates at my gym. I even do it when I'm holding my TIG torch.
"Well you know, it's a toolbox. You put the tools in for the job." Sam
I do it with chainsaws which probably has some merit.
The Minority Marksman.
"When you meet a swordsman, draw your sword: Do not recite poetry to one who is not a poet."
-a Ch'an Buddhist axiom.