"Mind! Don't let your head be the racecourse of others" -Arthur Schopenhauer (Germany)
I think what Schopenhauer wants to convey by this sentence is that you should think on your own and have your own opinion. Don't let yourself be influenced by the thoughts of others, and stand up for your beliefs. However, I'm not really familiar with Schopenhauer's philosophical theory.
"A week is a long time in politics."[/quote]
Either this one alludes to the fact that some things change often in politics, one day politicians make a decision that might already be obsolete the next day. Political matters often change very rapidly. Or it means that decision-making sometimes takes quite a long time in politics. I guess the first meaning is more logical as one week is acutally a short time for politicians to make a decision, amend laws, put forward suggestions, discuss issues, or things like that.
Interested in Language