Human thoughts tend to be manipulations of memories associated with either anxieties or desires. We either want things or want to avoid things.
When we start running into trouble is when our desires are not met by what is healthy (i.e. what we really want) but by what is unhealthy. If we continue to treat healthy desires with unhealthy replacements, we can develop a taste for what is unhealthy. Our minds will soon tell us that we want the unhealthy thing.
To want or to desire is not unnatural, and so overcoming our nature is really a futile task. No matter how hard you try, you will always want something, because we are meant to absorb and emit the things we receive. What I mean is that you will always desire water because your body is always losing water. You will always want to love someone because you will always want to be loved. Human beings have bad gaskets: we leak.
I saw this story in the news and thought I would share it because it talks about how stirring up desires through the media (as an example) can lead to acting out:
If we 'absorb' things by taking them into us and contemplating them, eventually they will come out. By taking in this imagery and stirring up the natural desire for sex, even when it is not appropriate, eventually the activity will come out.
This is why addicts do much better avoiding places and imagery of abuse. An alcoholic who hangs out in bars and watches people 'have a good time' can eventually stir up that craving for fun that he had when he drank (at least for a time), which will eventually lead to a relapse. In AA groups, alcoholics talk about those experiences, but also in light of the later suffering. Successfully sober people don't dwell just on the fun parts of drinking.
Sobriety means not feeding healthy desires for love and security with the craving for escape into abuse. It also means we should watch what we put into ourselves, so as not to unnecessarily stir the pot of desires. Daily life is hard enough.