"Stupid is what I have never underestimated," from James Patterson's book 7th Heaven, highlights the importance of not overlooking the potential for ignorance or foolishness in people. It suggests that underestimating stupidity can lead to unexpected problems or misjudgments, emphasizing the need for caution and awareness in decision-making and assessment of others.

The quote serves as a reminder to remain vigilant and not dismiss the possibility of poor judgment or lack of wisdom in individuals. Recognizing that stupidity can be more common than we assume encourages a cautious approach to interactions and assumptions about others' capabilities or intentions.