Fleeting Essence

I don't understand
Does my essence trickle out
Like blood from a wound
Yet I don't see it draining in a pool below
It simply disappeared
Like the soul from a dead man
Or a mischievous spirit from its last prank
Dancing like the wind around me
It taunts me with its existence
As it flits from me to some unknown abyss
Returning again only to leave
Perhaps it will resume its stay
Once I shake the fog from my mind
Caused by adding one more book to the already teetering stack