The title explains what this poem is about.

Gratitude to Old Teachers

Robert Bly

When we stride or stroll across the frozen lake,
We place our feet where they have never been.
We walk upon the unwalked. But we are uneasy.
Who is down there but our old teachers?

Water that once could take no human weight-
We were students then-holds up our feet,
And goes on ahead of us for a mile.
Beneath us the teachers, and around us the stillness.

from Eating the Honey of Words, 1999
HarperCollins Publishers, New York, NY