Bipolar
One Experience

Depression
Not Sadness, but incapacition, darkness, and emptiness 

Mania
Not Happiness, but creation, light, and fullness

Neither is good nor bad.  Each is needed to understand the other.

Bipolar people are gifted with glimpses of how profound our existence is--how tenuous and spectacular.  The ability of experience both allows one to experience the full breadth of life.  But experiencing the extreme of either can be deadly.