In August, Hart launched the 30-day challenge: Say “hi,” “hey,” or “hello” to one stranger every day for a month. “Let’s say you finally say ‘hi’ to someone in your fitness class. And yes, my nervous system learned to read those flutters in my body as a sign of excitement rather than danger. Homburger said this response makes sense because “when we engage in small social interactions, we experience pleasure through our dopamine reward pathways. AdvertisementBeyond dating, saying “hi” to strangers made me feel more connected to my community and the world around me.