It is late at night, and your body feels very tired. However, your brain will not switch off and keeps thinking. People call this frustratingfrustrating/ˈfrʌstreɪtɪŋ/L2令人沮丧的；使人懊恼的making you feel annoyed or upset because you cannot do what you want state being "wired but tired." A long time ago, this responseresponse/rɪˈspɒns/L2反应；回应what your body or mind does as a result of something that happens helped humans survivesurvive/səˈvaɪv/L2幸存；存活to continue to live or exist, especially after a difficult situation immediate physical dangers. The brain prepared the body to run or fight to stay alive.
Today, the world is very different, but the brain still uses this ancientancient/ˈeɪnʃənt/L2古代的；古老的very old; from a long time ago plan. Modern threats include stress from school, work, and social media. Because these daily stresses do not end quickly, the brain stays on high alert. The brain releases stress hormones which keep the body awake and ready for action. As a result, a tired body and an active brain often happen together at night.
However, there are ways to calm the brain and help it fall asleep. A consistent bedtime routine and less screen time at night can signal safety. Therapytherapy/ˈθerəpi/L2治疗；疗法a treatment that helps someone feel better, either physically or mentally for insomnia can also break the cycle of worry and sleeplessness. It helps people change their habits and negative thoughts about sleep. Feeling "wired but tired" is not a failure but a sign that the brain is working too hard in a modern world.
