From Ren & Stimpy, happy happy joy joy is defined as when the world expects you to put on this happy and joyful face when what you really want to do is shriek at the top of your lungs and rip your hair out in anger/frustration/misery.
Happy Happy Joy Joy
Just as you were ready to leave work for the day, the boss tells you he wants you to work both Saturday and Sunday on the new project. You’re on salary and so will get no more $$ for sacrificing your weekend. However, the boss is considering you for that vacant position where you’d have your own office with a window, so you happy happy joy joy and say, “Sure thing, boss!” with a big toothy grin on your face.