What about the changing meaning of words?
The word "gay" has done a complete about face. Once meaning "happy", "gay blades" meant "swashibuckling pirate types" like Errol Flynn or Burt Lancaster.
Later it came to be a politically correct term for homosexuals. In modern playground use it means "lame" as in,"That shirt is so gay."

The word "reality" has come to mean putting people in artificial situations and manipulating their actions.

Even the symbol "@" which used to mean "at $X a piece" has now become "at". Since it takes 2 fingers to type "@" or "at", why change it?