One of the other cures for grumpiness is to encounter a worldview that exposes the essential small-mindedness of the grumpy spirit. A theological critique of grumpiness isn't so much an analysis of whatever it is that disorders the self, as the posing of an alternative vision of what is important in life. So when I came across these lines from Bonhoeffer's Letters and Papers from Prison my spirit was lifted above the basement level grumpiness threshold to look again at the world through the eyes of faith, and to consider the essential selfishness of complaining that reality wasn't configured sufficiently around my own interests.
It is only by living completely in this world that one learns to have faith...By this worldliness I mean living unreservedly in life's duties, problems, successes, and failures...experiences and perplexities. In so doing, we throw oursleves completely into the arms of God, taking seriously not only our own sufferings, but those of God in the world - watching with christ in Gethsemane.
It's the word 'unreservedly'. Grumpiness is not much more than an inner list of reservations, complaints, criticisms, resentments which culminate in a spirit of holding back. Worldliness is the opposite - an engagement with the world in the name of the god who loved the world, loves the world, and will never rescind the fiat, "let there be".