Complex sentence: In 1973, Wallechinsky fed up with almanacs that regurgitated bare facts, had the idea for a reference book to be read for pleasure; a book that would tell the often untold true tales of history.
Split into simpler sentences: In 1973, Wallechinsky became fed up with almanacs that regurgitated bare facts. He had the idea for a reference book to be read for pleasure; a book that would tell the often untold true tales of history.