Acting, not prostitution, is the oldest profession in the world.
Developing a characterization is not merely a matter of putting on makeup and a costume and stuffing Kleenex in your mouth. In acting everything comes out of what you are or some aspect of who you are. Everything is part of your experience. We all have a spectrum of emotions in us. It is a broad one, and it's the actor's job to reach into this assortment of emotions and experience the ones that are appropriate for his character and the story.