Picture the blackest of nights. The sky is cloudless. It's warm enough to be sitting outside, and you're sufficiently far from sources of artificial light that your eyes can take in all the heavens have to offer.
What do you see? The chances are, you'll be staggered by the vast array of stars up there. Although experts differ somewhat in their view, it seems likely that in perfect conditions around two thousand are visible with the naked eye from any one place on the surface of our planet, and many many more when you peer through a telescope.
But the thing is, those two thousand stars are there all the time, even when you can't see them. In fact, even as we speak they're above your head at this precise moment. Clouds, ceilings and daylight may make them invisible to you, but they're right there, right now.
Of course it's not just stars that form a rich potential feast for your eyes. Everywhere you look, there's more to see than most of us for one moment imagine. Your world is full of detail and wonder, yet on a low day you may (like me) wander through it paying scant attention, eaten up with your own negative thoughts. Oh yes, I know what this is like.
However at any one microscopic moment, your mind can hold just a single thought, and it's a relatively simple trick to make this a neutral one (as you actively engage with your environment) instead of the unhelpful ones which are probably churning round and round in your head.
A night sky can be breath-takingly majestic. With an open mind, so can a walk down the street.