I've been taking pictures since I was old enough to be trusted with my father's old Leica. I must have been ten years old. The old man never let me use a light meter, insisting that I gauge my settings by eyeballing the sky. Of course, my photos were often under or over-exposed, because it's very difficult to make those sorts of judgments with any accuracy. There's a reason they make light meters. It did teach me about shutter speed, film speed, and aperture, though. These days, my camera does the calculating, of course, but it's helpful to know these things... and to break the rules to your advantage.