Why do we cry when we're happy? Science has some theories. "One possibility is that happy crying really isn’t that different from sad crying. What both have in common is a period of intense emotional arousal. Indeed, brain regions associated with emotional arousal, including areas of the hypothalamus and basal ganglia, are connected to a section of the brainstem called the lacrimal nucleus that stimulates tear production." There is also the possibility that "happy crying can help to strengthen mutual bonds between people." But if you ask me, we cry when we're happy because we know it's not going to last.
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