"The only reliable cure for overthinking seems to be enjoyment, something that both success and analysis can dull." This point at the end seems a bit forced without any support beyond the author's assertion. The feeling I get is someone who has mastered this unthinking is "enlightened" of sorts with an ability to get to satisfaction with a humility that can be mistaken for smugness.

From fiction, I might refer to the Wheel of Time series where Rand Al'Thor uses a trick to "find the void" in a way his father taught him. When you get overwhelmed from information and emotions, finding the void allows you to regain composure and think straight again.