One of the most difficult issues in getting a good exposure is contrast. The problem is that both digital sensors and film have a limited dynamic range--the range between brightest and darkest tones. When you go beyond that range you start to lose detail in either the highlights or the shadows (depending on which exposure decisions you make). If you expose for the bright areas you end up with shadows that are pure black with no detail, and if you expose for the highlights, you get whites that look very washed out.
Does this mean you can't shoot in very contrasty situations? No! You can actually exploit those contrast limits to create very dramatic images. Since there's usually not that much visual information in shadows anyway (there are exceptions to that), what I tend to do is to expose for the brightest areas where I want detail and let the shadows go dark. That's exactly what I did in this shot of daffodils: I took a reading (in matrix mode) with the flowers in the center of the frame and then shot at that exposure. I knew that the flower stalks and the greenery around the blossoms was going to go dark, but I like the way the lighting spotlighted the bright yellow daffodils.
I shot this photo in the late afternoon, by the way, just before the sun disappeared behind a hill. That late sun is very low angle, of course, so it helped with the spotlighting effect. The light, while it was fairly intense, was also very warm, so that helped too. By exposing just for that highlights though, it saturated the warm lighting and the colors in the flowers.
Next time you're faced with a contrasty situation that seems impossible to expose for, try taking a reading from the brightest object where you want detail and let the shadows go dark--it's a contrasty look, to be sure, but sometimes also very dramatic.