An equation of/for insomniacs:
A=The olfactory nerve, or cranial nerve I, is the first of twelve cranial nerves. The specialized olfactory receptor neurons of the olfactory nerve are located in the olfactory mucosa of the upper parts of the nasal cavity.
B=The limbic system is a term for a set of brain structures including the hippocampus and amygdala that support a variety of functions including emotion, behavior and long term memory.
A leads to B, thus by stimulating A then the impact upon B has an effect upon C.
Answer: inhale an intoxicating aroma. One travelling in air particles, or one derived from an immaterial entity. Relax and surrender to the unrealised potential of youself.