I am more with Kjj on this one. DD took off at 2 one time, when I couldn't get past a bunch of people, all with strollers. Another mother grabbed her before she went into a busy street.
She was bent on having her way and what she was doing. A year later, a boy in her space camp saw her at the band playing on the beach and when his mother wouldn't let him watch fireworks with her, he talked Dd (he was 4, she was 3) into running off, hand in hand, down the boardwalk while his mother and I were running after them.
The older they get, they can create very "logical" reasons for what they want to do. If you are not one step ahead of this gifted child, then God help you when puberty hits. They'll be like me, throwing parties for 400 people, so they can build social skills.