Follow the path of the unsafe independent thinker. Expose your ideas to the danger of controversy. Speak your mind and fear less the label of 'crackpot' than the stigma of conformity.
But for me it is when a student has died. I find the death of a young person the most difficult and painful of times. To explain it to other young people to see a bright future snuffed out is just awful. I am haunted by those deaths.
