In general, happiness is understood as the positive emotions we have in regards to the pleasurable activities we take part in through our daily lives.
Pleasure, comfort, gratitude, hope, and inspiration are examples of positive emotions that increase our happiness and move us to flourish. In scientific literature, happiness is referred to as hedonia (Ryan & Deci, 2001), the presence of positive emotions and the absence of negative emotions.
Extending B. L. Fredrickson’s (1998) broaden-and-build theory of positive emotions and M. Losada’s (1999) nonlinear dynamics model of team performance, the authors predict that a ratio of positive to negative affect at or above 2.9 will characterize individuals in flourishing mental health. So, even if your light was off sometimes, it is ok. You don't need to be happy 100% of the time. Afterall, we are all human.