The first statement - it makes no sense to expect good things to happen - is just false. Our very existence is good, and other good things happen all the time. Births, weddings, rare steak, etc.
The second, that all things will break and we should expect that, is more or less true. We live in a fallen world, and we will all die, and at some point even the earth will be destroyed by the sun.
But physical things are not all things. So I think the takeaway is that physical things are transient, and so while there is nothing wrong with them or with enjoying them, it would make more sense to look to the things that last first. It demonstrates a need to prioritize what is truly important and lasting over what is transient, even if good.
Or in short: what does it profit a man to gain the whole world if he loses his soul?