Law 18

From the 48 Laws of Power...

 Law 18 

Do Not Build Fortresses to Protect Yourself - Isolation is Dangerous
  The world is dangerous and enemies are everywhere – everyone has to protect themselves.  A fortress seems the safest. But isolation exposes you to more dangers than it protects you from – it cuts you off from valuable information, it makes you conspicuous and an easy target.  Better to circulate among people find allies, mingle.  You are shielded from your enemies by the crowd.

Start tearing down those walls folks....at the very least make yourself a window.