These quotes are repeated over and over at night until they are conditioned into people, especially betas like Lenina. The World State relies on high levels of consumption to support its industry, and this means people need to keep replacing goods rather than mending them. In this case, both quotes pertain to clothing. Betas are encouraged to replace clothing that has ripped in some way rather than sewing up the clothing so they can wear it again.
This is of a piece with complicated games that need multiple parts: if people don't keep consuming, a whole series of economic problems will ensue. It's also a symbol of the superficial, disposable nature of this culture. Anything damaged or ugly is put out of sight.
We need to keep in mind, too, that this novel was written in the early 1930s, when levels of consumption were much lower than they are today, and when the idea of throwing out clothes rather than mending them would have been both more shocking and more laughable than it is now. Now, our society more closely replicates the World State in terms of consumption.