100% concur. My kids seem to have developed a sixth sense for when I'm deep in thought on a particularly hard problem, and will usually pick THAT EXACT MOMENT

100% concur. My kids seem to have developed a sixth sense for when I'm deep in thought on a particularly hard problem, and will usually pick THAT EXACT MOMENT to gang up on my wife. In unison, all 3 will have temper tantrums, causing my wife to call down to me (I work in the basement) for backup. I suspect this is related to the ability for an infant to know the difference between your REAL cellphone and your old cellphone with the SIM removed. Seriously. I've never met a baby who was happy playing with an old cellphone, but give them a working cellphone and they're totally happy.