Introspection is essential to mastering life. The quality of involvement in activity, and connections that come by interactions with others, cannot be assessed without careful self-reflection.
Inward focus is increasingly lost as lifestyles impose high-attention demands, without the opportunity for contemplation. Portable devices that afford texting and constant communication are introspection assassins.
A quieted mind is not idle. Subconscious mentation never ceases. Constructive internal reflection is critical to contextual learning, and allowing intelligence choices for the future.