Author Morgan Housel observes that even life-changing non-fiction books aren't remembered in their entirety. Their lasting impact comes from two or three memorable sentences or core ideas that the reader internalizes. For authors, this reframes the goal from comprehensive recall to crafting a few powerful, sticky takeaways.

To communicate complex ideas, write at a 4th or 5th-grade level. Warren Buffett, a master of a complicated business, writes his famous annual letters with extreme simplicity. Using simple language and analogies makes your message more accessible and powerful, not less intelligent.

Humans naturally conserve mental energy, a concept Princeton's Susan Fisk calls being 'cognitive misers.' For most decisions, people default to quick, intuitive rules of thumb (heuristics) rather than deep, logical analysis. Marketing is more effective when it works with this human nature, not against it.

Trying to be overly clever with metaphors or complex language can distract and confuse an audience. Simple, direct narratives—like a "Dick and Jane" book—are more effective because they ensure the core message is easily understood and retained.

Morgan Housel finds that the content that performs best is often basic and seems obvious to the writer. Readers resonate with ideas they already intuitively feel but have never seen articulated. This connection requires less mental bandwidth than processing a completely novel concept, leading to wider sharing.

Donald Miller argues that purchases are driven by words that are easy to understand, not by brand aesthetics. Making a customer think is a barrier to a sale. Simplifying your message to reduce mental effort is more effective than having a beautiful website or logo, as exemplified by Amazon's success.

Your promotional content must be immediately understandable to a distracted audience. If a 'drunk grandma' couldn't grasp your offer, it's too complex. Simplicity sells better than a superior product with confusing marketing because 'when you confuse, you lose.'

Extensive behavioral research on ad performance reveals a clear pattern: simplicity is superior. Creatives with multiple storylines, clutter, and excessive detail create cognitive load and reduce effectiveness. The best-performing ads feature a single, clear message that is easy for the human brain to process quickly.

The "midwit" trap is thinking you're the genius and overcomplicating things. A better approach is to actively simplify your solution to a level an "idiot" could understand (e.g., "calories in, calories out"). This often leads to the same simple, effective answer the "genius" would arrive at.