Pastorale in classical music is best defined by the feeling. It is slow, and reminds you of the pastoral lifestyle, particularly the shepherds. It is supposed to evoke country scenes - considering that the country is clean and tidy and people are stress-free. Does this seem idealized? It may to the urban readers. It may also touch their heart, make them want to lead simpler yet richer lives. It is not a fantasy.
My definition of Pastorale is -- that which makes you reach within the peace of your heart. The pastorale music reminds you of that peace. It soothes you, makes you remember what you always wanted. Therefore, it is not a fantasy. It may be fantasy for people who have given up in general.
Here are some instances that will tell you about the pastoral lifestyle.