Saṃvega
Saṃvega is a Buddhist term which indicates a sense of shock, dismay and spiritual urgency to reach liberation and escape the suffering of samsara. According to Thanissaro Bhikku, "saṃvega" is the "first emotion you're supposed to bring to the training" and can be defined as: The oppressive sense of shock, dismay, and alienation that come with realizing the futility and meaninglessness of life as it's normally lived; a chastening sense of our own complacency and foolishness in having let ourselves live so blindly; and an anxious sense of urgency in trying to find a way out of  the meaningless cycle. "Saṃvega" is also associated with the development of energy ("viriya") and right effort, according to Buddhagosa's Atthasālinī: Energy has exerting as its characteristic, strengthening the co-existent states as function, and opposition to giving way as manifestation. It has been said: "He in whom "saṃvega" is present exerts himself properly," hence energy has "saṃvega", or the basic condition of making energy as proximate cause. Right exertion should be regarded as the root of all attainments. - DhsA. 121 There are eight bases of "saṃvega" ("saṃvega vatthu"). They are "birth, old age, sickness, death, suffering in the woeful  worlds, the round of suffering as rooted in the past, the round of suffering as rooted in the future, and the round of suffering in the search for food in the present." "Saṃvega" can therefore be developed by practicing meditation on death (maranasati) and the charnel ground meditations as outlined in the Satipatthana sutta. In the Upajjhatthana Sutta the Buddha taught that everyone (monks and householders) should practice the five daily recollections as a way to arouse energy and "saṃvega". For "saṃvega" to be an effective drive to practice, it must be accompanied by another emotion called "pasada", a "clarity  and serene confidence." "Pasada" is what keeps "saṃvega" from turning into nihilistic despair by providing a sense of confidence that there is a way out, namely nibbana.