Things could be different than they are. Everywhere we look, we take it for granted that this is the way that things must be. However, it really only is the way they are here, now and as we perceive them.

Consider clouds. We can see them, however it does not necessarily have to be that way. It could have been that it had the same refraction and reflection as air. This would result in clouds being invisible (or at least indistinguishable from the rest of the sky). It would always be sunny. There would never be overcast days (notwithstanding smoke, ash, dust, pollen and other air borne particles). It would always be sunny when raining (unless it was night). There also might not be any rainbows.

The sky would be much more boring. Or would it? It would just seem normal. Afterall, there are likely some things that are very plain to use that could have been full of variety.

Until we experience such altered realities, one might as well enjoy the clouds in the sky.