An image often used to describe the practice of insight is that of walking a tightrope.
As we are walking the tightrope, it becomes clear that the one thing we must pay attention to is balance, maintaining perfect poise. While walking on the tightrope, different things come whizzing by us, different sights, and sounds, emotions, ideas, and realizations. If these are pleasant, the conditioned tendency of mind is to reach out, trying to hold onto them, trying to make them stay. If the sights and sounds are unpleasant, the tendency of mind is to reach out in aversion, trying to push them away. In both cases we reach out, and in the reaching, lose our balance and fall.
Both the positive and the negative reactions are equally dangerous. Anything at all, however glorious or terrifying, which causes us to lose the perfect balance of mind, makes us fall. So we work again and again to develop a mind which doesn't react with clinging or condemning, attachment or aversion, to any of these objects. Developing a mind which clings to nought, to absolutely nothing, just allowing it all to come and pass away.
Joseph Goldstein: The Experience of Insight: A Natural Unfolding