With so much emphasis on dukkha, on overcoming the five hindrances, etc., our practice can at times seem bleak. We can balance this and lighten the heart by knowing where and how to find the joy in practice.
As the Buddha showed, clinging gives birth to the I. The I, in turn, keeps puffing itself up by further clinging. When we understand that this generates nothing but suffering, we are ready to unlearn the I, that is the "Me."
Contact brings impressions into the heart, which gets retrained at an involuntary level and affect our immediate response to life in terms of fear, mistrust, desire. There are ways of clearing this—the result is joy.