The important thing is not to worry about important things. Plural because I am sure there are many important things out there and they change from person to person, sometimes minute by minute.
The important thing is to remember that whatever it is that is important now is temporary. It is fleeting.
Important things can be categorized as impossible to categorize by anyone except you. But the important thing is to remember that both you and the important thing at the moment you consider it – whatever it is – are changing and there is no permanent thing anywhere.
The important thing is to look at important things in the same way we look at the ocean, or a river, a stream. What we see looks like a single thing, and so we have a name for it, but that is an illusion, or at least a trick we allow ourselves to fall for so we can admire the view without getting too tied up in questions of waves and ripples.
The important thing is to think about it all, ourselves to start with, in terms of waves, or ripples. These things look like they are moving in a direction and perhaps rebounding off obstacles, finding a way around them. In one way, they are but not if you simply consider that a molecule of water is just moving up or down, and maybe side to side ever-so-slightly to give the observer the idea that something larger is moving much faster.
The important thing is not to think too much about things we cannot understand, especially if you fancy our chances of illustrating the complexity of life with wishy-washy comments on the movement of bodies of water.
The important thing is that everything is important to someone at some time, in some circumstance. Likewise, everything is unimportant. The important thing is to remember that everything moves, everything changes and if you sit still and quiet for long enough, the important things will not need to be worried about.