Worn joints. Just like the other joints in your body, your neck joints tend to wear down with age. Osteoarthritis causes the cushions (cartilage) between your bones (vertebrae) to deteriorate. Your body then forms bone spurs that affect joint motion and cause pain.
As the user guide explains, kids hardly read (and you canât expect a 3 year old to read!). So you get games which teach you about letters and numbers starting from the real simple ones to others that teach more fundamental things like reading time or guessing colors.
As Jenny points out, being able to lisp the alphabet song at age two has little to do with 'knowing' the alphabet. And, yes, most children learn the letters by sight and sound in kindergarten, although most are capable of learning this information sooner if diligently taught by parents or others.