"Good communication is as stimulating as black coffee and just as hard to sleep after". - Anne Morrow Lindbergh, from her book 'Gift From the Sea'
The comparison is funny but true: Coffee contain caffeine which is a stimulant to the mind same as a good communication. when we communicate effectively and closely, we feel attracted to the discussion and very much focused. Coffee would do the same effect to energize our day and stay focus on what we are doing.
Of course that equation won't work with people who don't like coffee, as well as for those who don't communicate much, and thus they will be stimulated by many other things: what might stimulate you? 😉