Most of us have been thoroughly trained to be "nice." The 2-part Rule of Nice goes like this...
Part 1: Only say and do things that please others.
Part 2: If you feel like saying or doing something that might possibly displease someone, see Part 1.
So, to obey the Rule of Nice at all times, you have to get pretty good at not being authentic. But being inauthentic is not very nice, so the only way to win this game is not to play it!
Children are naturally authentic, which means they often aren't "nice." You're supposed to pressure them to obey the Rule of Nice, but wouldn't it be nicer to let them inspire you to be more authentic?