A funny story
A professor in the science of English grammar undertook a sea voyage.
During the voyage, he asked the sailor whether knew anything of
the science of grammar.
The sailor replied that he did not.
“Then you have lost one half of your life” said
the professor.

Later, a violent storm blew out. Wind and waves swept and tossed the vessel
like a feather, and the small ship was about to sink.
The sailor came near the grammarian and
asked him, “Do you know how to swim, sir?”
The grammarian replied sadly that he did not.
The sailor smiled and said to him, “Then you have lost all your life