The suprachiasmatic nucleus (SCN insomnia. As well as having a harder time asleep, you also will likely have trouble asleep. Not following circadian rhythms may result also governs your body temperature, hormone secretion, urine production, and changes in blood pressure. This complex system is also automatically linked with the rhythms of light and dark, day and night. A nearly immediate effect of going to bed after midnight is that it throws off your natural circadian rhythms, governed by your SCN, and this may lead toin a decrease in activities that tend to occur during Non-REM sleep. These include repair and regrowth of body tissues, building bone and muscle, strengthening the immune system, regulating affective brain function and emotional experience, memory activities, and an ability to learn. My mother used to say, “The two hours of sleep I get before midnight are the best two hours of the night.” She may have had something there . . .