It was common lamentation for guys who lost girlfriends to the glitter of Californian show biz. Hollywood, LA and SF, the centers for movie stars and pop stars are all there. Girls seeking fame and fortune would forsake hometown loves if there's a chance to give it a shot there. In fact, guys too of couse, and there's another song on that theme about the same time as A Whiter Shade Of Pale. It's called It Never Rains In Southern California.