The “I’m up so where is my milk/breakfast?” situation.
Why do they think that shouting at your eye will do it? Then you have exactly 20.3 milliseconds to hope your nervous and muscular systems have come to enough to deflect the chubby finger headed towards your cornea.
Effective, undoubtedly, uses far fewer batteries than an alarm clock or phone alarm and is pretty much bang-on time EVEN ON WEEKENDS until BST and GMT start playing their games but really? Is this some kind of technique they learn in nursery?