The many moods that we display every day, even minute by minute are generated in the mind. The brain, which is the "physical mind" has a wide variety of ready-made moods left over from childhood, new moods just learned and also moods that work for us in specific circumstances, tried and true-like old friends.
Moods are results of neurotransmitters in the brain:
Serotonin creates anxiety, sensitivity, overly emotional and obsessions.
Dopamine creates motivation and feelings of wellbeing or euphoria.
Norepinephrine creates focus, attention, energy and organization.
There are hundreds of neurotransmitters in the brain, somehow we only concentrate on these 3!