The title, is a Sufi thing. 'All structures are not safe' refers to the impermanence of everything.
Hinduism talks of 'yugas' which are basically cycles, eras, of things, people and Gods. Usually Gods.
Buddhism talks about how everything is not permanent. How things are in a constant state of flux. This, too, shall pass.
Omnia mutantur, nihil inherit (everything changes, nothing is truly lost), wrote God of Writing Neil Gaiman.
"Sit on the riverbanks long enough, and you will see the bodies of your enemies floating by," wrote Sun Tzu.
Given a long enough timeline, everybody's survival rate drops to zero - Tyler Durden.
Oh, it's true, it's true - Kurt Angle.
I am now in a state of peace and happiness. As with all states, and as with everything, this will one day pass.
I'm happy now, but one day, maybe some who are jealous of me would come and try to poke me. I might allow my ego to take over and react to their idiocy.
Something bad might happen. Some people might die, and I might allow myself to be consumed with sadness and hatred.
I don't know what will happen in the future.
I do know that I am happy now, even with the realisation that someday, this, too, shall pass.