A Critical Period

Rav Yechiel Michel Stern, shlit”a, explained the significance of becoming bar mitzvah in a very inspiring manner. “Imagine people watching a film in a dark room. Someone walks in and wonders what will happen if he shines some of his own light on the screen. Will the images be sharper or dimmed? Of course, the moment he flips on his powerful flashlight and shines it on the screen, the image is seen for what it really is: a collection of lights that does not represent reality. People will likely insist that he stop ruining the image with the extra illumination.
“The same is true regarding illicit desires and sin. The image seems compelling only as long as one refrains from shining the light of the intellect on the image. The moment he puts it into proper perspective, it is shown to be nothing more than an illusion.
“Our sages say that the yetzer hara is compared to a fly. Like a fly which thrives on a wound or rot, but does no harm to healthy skin, our yetzer hara needs an opening to make his mischief. If one is vigilant and seals any possible entrances with his newly acquired yetzer tov, he has nothing to worry about.”
Now we can understand why a ben sorer u’moreh is only punished from bar mitzvah until three months after bar mitzvah. This time is so essential for setting safeguards and becoming a mentch that if one follows in the ways of a ben sorer u’moreh during this time, he will certainly follow an evil path for the rest of his life. Of course the rule is that the good outweighs the bad. We see from this that one who uses these three months properly, to strengthen his connection to Hashem and accept the yoke of heaven, he will surely go in a good way and live an upright life!”