Undergrowth

It ain’t the trees that block the trail,
It ain’t the ash or pine;
For, if you fall or if you fail,
It was some pesky vine
That tripped you up, that threw you down,
That caught you unawares:
The big things you can walk aroun’—
But watch the way for snares.
In life it ain’t the biggest things
That make the hardest load;
It ain’t the burden big that brings
Defeat upon the road.
Some fault you hardly knew you had
May hurt more than you think—
Some little habit that is bad
May put you on the blink.