Most humans are prone to addictive behavior, some more than others. The path to addiction is a one-step-at-a-time advance. It is an effortless step from one stage to the next. Step 1: Involuntary Repetition (internal cycles and rhythms, such as breathing, heartbeat, sleep) Step 2: Voluntary Repetition (behavioral cycles, cultural rhythms) Step 3: Habituation (repeated patterns of voluntary behavior over long periods of time) Step 4: Compulsion (compelled toward something, or someone) Step 5: Obsession (powerful urge to engage in habitual behavior) Step 6: Addiction (uncontrollable habituation; dependence) Addiction can occur either by ingesting chemicals, such as alcohol or tobacco, or by external behavior, such as sex or gambling. Both elevate levels of dopamine, and, if unchecked can lead to addiction. The attempt to retreat from addiction is excruciating, uncompromising, and often ineffective. Having arrived at the mountain of desire, there is no going back. Similar to a lobster trap, or marriage contract, it is easy to get in, painfully difficult to get out. What is it about the nature and chemistry of the human brain, the nervous system, that makes addiction inviting on the one hand, and so debilitating on the other? From the point of view of evolution, it makes little sense that the brain would cooperate so completely with its own downfall.