In buddhism, the second “noble truth” states that suffering is caused by attachment. Taken on its own, it is about recognising the truth of this, whether or not there is anything we can do about it (according to buddhist philosophy there is, but other noble truths handle that).
The idea is that simple. All suffering in life is due to attaching, or clinging, to things: to the self, and notions of our self, to other people, to physical possessions, to ideas. Whatever. It always causes suffering. Like a law of the universe for living things.
All “worldy things” are transient, so it goes, and when we attach to them we are in for a world of hurt. Just like if we formed an attachment to something in a dream, the same thing applies to attachments formed in waking life.
We think we can “have” things in real life, whether physical objects, aspects of people, or something more conceptual or emotional, and that we can safely attach to these things we have. The second noble truth says otherwise. All we can “have” is delusions, and all attaching will do is cause suffering.
It seems like a harsh, cold truth. It is — at least, when you are attached to the idea of attaching.
To get a bit Lynchian: we live inside a dream. When we attach, it becomes more like a nightmare.
I have been meditating for years, and quite often I will run through the four noble truths in my head to give me focus. Not as a strict rule — much of the time I meditate with a more scientific or biological outlook, as a form of mind maintenance, without focusing on any specific buddhist ideas.