The kindergarten class had a homework assignment to find out about something exciting, and to relate it to the class the next day. When the time came for the little kids to give their reports, the teacher was calling on them one at a time. She was reluctant to call upon little Wally, knowing that he sometimes could be a bit crude. But eventually his turn came.
Little Wally walked up to the front of the class, and with a piece of chalk, made a small white dot on the blackboard, then sat back down. Well the teacher couldn't figure out what Wally had in mind for his report on something exciting, so she asked him just what that was.
"It's a period," reported Wally.
"Well I can see that," she said. "But what is so exciting about a period."
"Darned if I know." said Wally. "But this morning my sister said she missed one. Then Daddy had a heart attack, Mommy fainted and the man next door shot himself."