When your mood is low, it's easy to feel the details of life crowding in on you. It's easy to feel trapped by the sheer complexity and messiness of everyday life.

The fact is that when something is distressing us, we feel part of it, even responsible for it. And that makes it difficult for us to stand back and see what's really happening.

Next time you feel like this, try to see the bigger picture - take a mental helicopter ride. Imagine going higher and higher. As you get further away, the details that disturbed you at ground level disappear and new shapes emerge. It's the same idea behind the saying We Can't See The Wood For The Trees.

Another way to think about this distancing effect is consider the zooming function on Google Earth. On the close-up view, you can see individual houses, twisting networks of roads and so on. But zoom out, and a completely different view emerges - towns and cities and fields and great rivers. Zoom out further, and we begin to see countries and continents.

For the ultimate example of shifting magnitudes, search out Powers of Ten on You Tube. You'll be amazed.