Late

“It was terrible”, moaned John upon entering the classroom a half hour late. “I left with plenty of time to arrive at school on time, but it was so slippery that every step I took, I slipped two steps back.” “Well,” said the teacher, with a suspicious look on his face, “how in the world did you get here at all?” “Well”, said the quick thinking student, “finally after twenty minutes I gave up and started heading home!”