Why is the three-year-old disobedient? Three years old is the age when children are most willful, curious and self-aware. During this period, children are often disobedient, which makes parents feel very troubled. So why do three-year-olds often disobey? First of all, children\’s discrimination and memory are still developing, and they cannot understand and remember adults\’ words immediately. Secondly, children begin to gradually experience a sense of self-existence during this period, and sometimes show rebellious and stubborn traits. Finally, parents may have improper methods when educating their children, or may have negative attitudes toward their children.