The Buddha says that the root cause of suffering is attachment.

As yogis, we intellectually know this to be true, yet continue to remain attached to this idea of ownership -- "our" life as a healer, a yogi, a humanitarian. The I-ness and my-ness is something we actually believe to be true, thus taking on pain and seeing the emotions as real. The will is driven by desires and desires in turn lead to gratification, which then leads to the desire for more gratification which eventually leads to suffering. If we're able to direct our divine will as such that creates a neutralization we will end all suffering and experience true peace. There is a fine line that we walk along when looking to remain still yet move through and transcend.

It's that feeling you get when you feel everything is going to crumble all around you, yet that realization that there is really no loss, but rather a fear that mind creates through manipulation and attachment. The attachment to the idea of life being a linear process (i.e., a beginning, climax and ending), will only lead to suffering. The Buddha teaches to stop. Let go. And allow all desires to cease, as the ripples in a lake slowly stopping. Question: how can you place your finger in a bowl of water without creating ripples? It's all about focusing the mind and letting go. Then dissolving all of it into Truth.