Good communication is just as stimulating as black coffee, and just as hard to sleep after.

Lindbergh likens a truly engaging exchange of ideas to a strong stimulant: it energizes, sharpens attention, and can leave the mind buzzing long after the conversation ends. The comparison suggests that communication is not merely functional (transferring information) but experiential—capable of producing a physiological and emotional aftereffect. Implicitly, the line praises conversations that are candid, intelligent, and alive, while also acknowledging their cost: mental wakefulness, rumination, and the difficulty of “coming down” afterward. The quote captures how meaningful dialogue can be both nourishing and disruptive, a pleasure that lingers and resists closure.