[TenaciousBadger]

Originally Posted by WT Sharpe

.....A teacher affects eternity; he can never tell where his influence stops.
..........— Henry (Brooks) Adams (1838-1918), American historian. The Education of Henry Adams: An Autobiography (Boston: Houghton Mifflin, 1918), page 300.

Perhaps he cannot, his students/disciples/learners, however, might be of a different opinion.