Sure. You're not following the program. You're not pretending to be happy, whether you are or aren't. That's just not done! They're not equipped to deal honestly with sadness! The gospel makes you happy!
Kalle, I hope your question is not prompted by any kind of depression in your life. Having just recently experienced a very young family member committing suicide over severe depression that he covered up very well with a smiling outward appearance, I am sensitive at this time to the issue. I hope I am wrong and that your life is full of wonderfully positive things but if it is not I would urge you to make any feelings of depression you might have known to those who care about you and who might be in a position to give you help. Forgive my if I am being presumptuous and over reacting in any way.