" She had always understood that love could have an intense physical effect; could fill a space somewhere in the chest, could turn knees weak, could raise the pulse; could intoxicate, just as could a strong martini or a glass of champagne. Could, she thought, and would…but only if you allowed it, only if you opened whatever portals of the heart needed to be opened. And some people, of course, found it difficult to do that. "

― Alexander McCall Smith , At the Reunion Buffet (Isabel Dalhousie, #10.5)