Continuous Growth

A Gemara in Shabbos says each Jew received two crowns when they answered "naaseh venishma". One for "we will do" makes sense. But what is so special about "we will listen and learn", when anyone must learn in order to do? And if the Midrash says each person heard the Ten Commandments at their own level, why did their souls leave them? The answers center on what a Jew's level actually is. Then the Chofetz Chaim's granddaughter comes to him with a challenge about the wider world, and his reply is worth hearing twice.