We were posting at the same time so I didn't see that you were refering to "an idea" not being a teacher. For me, it kind of goes in the same category as the rock. I can think of the idea to say a kind word to everyone that walks by and see the reation of the passersby. I then learn that the idea of "kindness" results in smiles or kind words in return. I can also think of the idea to trip every tenth person and see what happens. I will probably learn that the idea of "meanness" will result in a black eye.
I can argue with myself on this one since it may be seen that the people smiling or punching are ultimately the teachers of the lesson. How's that for talking out of both sides of my mouth. LOL