The Unicorn's tail

Let me not chase the unicorn's tail
its pointy horn not all I fear
in futility shall I not travail
to fellow seekers' disdain and jeer
and triumph is the sum of trine
a way with words, some decency
in which I know I fare fine
but may never catch its fancy
for fancy is but a bird on wings
high and mighty that tends to fly
I know not whence mightiness springs
whilst all know I am not too high
with this rant I give up my stakes
while the unicorn's tail mockingly shakes