At a fundamental level, Dopamine can be thought of as the physiological driver or currency of motivation and forward progress.
Dopamine is released by neurons and functions as a neurotransmitter, sending signals to other nerve cells.
Dopamine is modulated to signal the perceived level of pain or pleasure, desirability or aversiveness, associated with a future objective or outcome.
This modulation then drives the organism either towards or away from the goal or outcome.
The levels of dopamine in the brain predominantly increase in anticipation of pleasure or reward.
This is why being in pursuit of a Worthy Aim is crucial to success and wellbeing.