(Insight Meditation Society - Forest Refuge) Citta/heart is like a lake with waves rippling through it. The unawakened response is to create walls to resist the unpleasant, and fences to retain the pleasant - and ‘me’ to hold it all. Awakening responses to the waves are the skills of samadhi and brahmavihara. These make the lake vast and able to allow waves to arise and subside. They are doors to the Deathless - the unconstructed that the citta can enter through non-holding.