True words

There's a saying that goes a little like: if we forget history, we're doomed to repeat it. But what "makes" history? "On this day" gives little slices of it, and two of today's entries in The Daily Telegraph's column deal with famous "true" words. In 1912, with the words "I am just going out. I may be some time" Englishman Lawrence Oates, on his way back from the South Pole with Robert Falcon Scott, and celebrating his 32rd birthday with frostbite, left the tent in which they were sheltering - and died in a blizzard.
In 2003, citing as one of his reasons that he believed Saddam Hussein's regime did not have viable weapons of mass destruction, British cabinet minister Robin Cook resigned rather than support plans to invade Iraq.
In retrospect, both of these were statements that turned out to be correct. Would the course of history, as we know it, have been changed if, at the time, people had "heard" what they were saying - and acted accordingly?