I'm taking an introductory college physics course as part of my pre-med coursework, but unlike most pre-meds I actually like physics and want to understand the material beyond simply crunching the numbers. The equations are easy but some of the concepts are hard - espeically when you really think about them. We're studying basic e/m right now, and there's one issue I just can't resolve in my mind. I'm hoping one of you might have a moment to enlighten me, and I thank you in advance for your time and expertise. The question is how you can have high voltage without a great deal of charge, and vice-versa. For example, when you shuffle your feet across the carpet, you may acquire a potential difference of several thousand volts, right? As I understand it, this happens because you acquire lots of electrons. Yet when you subsequently touch a door handle, the shock isn't dangerous because, as a textbook will say, there's very little charge. To my half-informed mind, you can't have one without the other. Why doesn't building up high voltage require amassing a lot of charge as well? And conversely, how can a great deal of charge be stored up at relatively low voltage, such as in a car battery? Thanks very much in advance for your wisdom. My father, who was also a physician, knew e/m forwards and backwards and considered it by far the most important science. He'd hang his head in shame if I didn't mentally master this topic.