Well I like to support my answer with pictures as well as words.
Teachers 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.