Complex sentence: As David continued to grow (please note that David's body grew but his hands stayed the same size) he continued listing things and he frequently tried to "cut out the noise" as a youngster but was unsuccessful in doing so.
Split into simpler sentences: As David continued to grow (please note that David's body grew but his hands stayed the same size) he continued listing things. He frequently tried to "cut out the noise" as a youngster but was unsuccessful in doing so.