We have misconceptions about what is good for us and what not,
because we keep forgetting to ask the most basic question
`When I am in situation X, is what is going on in my body pleasant or unpleasant?'
In the middle of work, you get caught up in a sexual fantasy.
All your attention is in that thought, and none of it is in your body.
You assume it is basically pleasant,
but if you actually observe what is going on in your body at that
moment, you would feel mainly tension, contraction, discontent.
When you notice that, as you are not consciously masochistic, the
energy behind that thought automatically weakens.
This is how you can explore the natural law.
Whatever physical or mental action you take, see if it generates pleasant or unpleasant sensations in the body.