We can become restless and adverse to the breath because we always have the desire to get something. We want to find something that easily interests us, something we can focus on without much effort. If we find something interesting, such as exciting rhythmic music, we absorb right into it. But the rhythm of normal breath isn’t interesting or compelling. It’s calming, and most beings aren’t used to tranquility; they are caught in a need to be excited or interested. In other words most of us need something outside of ourselves to stimulate us and to engage our attention.
Ajahn Sumedho, The Mind and the Way