In medieval Japan, people used to carry with them sticks with little rice paper lanterns at their edge, to light the way in dark, foggy nights. Now, there was this blind man that a friend advised him to take a lantern with him too.
“Why do I need a lantern if I can't see the way anyway?”, the blind man wondered.
“You will not see, but you will be seen.”, his friend replied.
The blind man realized that this is a good idea and started carrying a lantern. Of course, doing so did make people stop bumping into him, a thing that happened so often that he got used to it. But one gets used to good things quickly, so after a while, when one day someone bumped into the blind man on a dark and foggy evening, he was very surprised and angry.
“I am sorry”, said the old man who bumped into the blind man, “but…”
The blind man responded in anger, not letting the old man explain, “But! But! Can't you see where you are going?!”
“But your lantern is off”, the old man replied calmly and walked away.