Teaching a practice can also be a hindrance if it becomes one's identity. To be a spiritual teacher is a temporary function. I'm a spiritual teacher when somebody comes to me and some teaching happens, but the moment they leave I'm no longer a spiritual teacher. If I carry the identity of spiritual teacher, it will cause suffering.
When we put our keys down, we should be conscious of putting them down. When we pick them up, we should be conscious of picking them up. That's all there is to zen.