You're absolutely right. Teachers have such a huge responsibility on their shoulders- they really can shape a life for good or ill with what they make kids believe about themselves, because the seeds they plant can be there forever- beautiful flowers if you're lucky, rampant choking weeds if you're not. A bad day in a teacher's life can translate to a bad life for the kids they're in charge of if they're not careful. They create this self-image which follows you into your future.
E x