A lot of people think changing careers will be a shortcut to happiness. (Kinda like people think having a baby or getting married or buying a house will finally make them happy.)But what if you could be happy in any career -- including the one you're in now?Here's a truth that might feel a little confronting.It's not your work that makes you happy. It's your thoughts.And the good news is that you get to think whatever the hell you want!It opens up the possibility that you could be happy right...