A true "habit" is a behavior done with little to no conscious thought. Trying to make intellectually demanding or physically strenuous activities like writing or intense exercise into effortless habits is a recipe for failure. These activities are routines that will always require conscious effort and should be treated as such.

The true sign a product has formed a habit is when users are prompted by internal, uncomfortable emotional states like boredom, loneliness, or anxiety. This self-triggering mechanism, not external notifications, accounts for 90% of phone checks.

Any behavior, emotion, or belief satisfying at least three of the six core human needs (certainty, uncertainty, significance, connection, growth, contribution) will become an addiction. This model explains the compulsive nature of both positive habits and destructive behaviors like violence or online trolling.

A habit is done with little conscious thought (e.g., driving). A routine is a series of frequently repeated behaviors that still require effort (e.g., meditating, writing). Mistaking a routine for a habit leads to frustration when the activity doesn't become effortless.

Habits are persistent neural pathways. Instead of trying to eliminate one with willpower, keep the existing cue and reward but consciously substitute the routine with a new, better behavior. This 'overwrites' the old pathway.

Contrary to popular belief, habits are not formed by repetition. The true mechanism is emotion. When you perform a behavior and feel a sense of success, that positive emotion wires the habit, making it more automatic. Strong emotions can form a habit in a single instance.

To curb bad habits, add friction to make them harder (e.g., move junk food out of the house). To build good habits, remove friction to make them easier (e.g., lay out gym clothes). This physical approach is more reliable than willpower.

A powerful definition of addiction is the gradual shrinking of a person's sources of joy. As the addiction takes hold, natural rewards like relationships, work, and hobbies fall away until the substance or behavior becomes the only thing left that provides a feeling of reward, creating a powerful psychological dependency.

Addiction isn't defined by the pursuit of pleasure. It's the point at which a behavior, which may have started for rational reasons, hijacks the brain’s reward pathway and becomes compulsive. The defining characteristic is the inability to stop even when the behavior no longer provides pleasure and begins causing negative consequences.