Matter is temporary. Newspapers and plastic bottle get recycled. Plants compost. The atoms that make up our bodies were once clouds of cosmic dust. Everything is recycled. Everything is temporary.
However, if we can remember things, they become permanent. A shirt can get cut up into rags, but if you remember wearing it, it's still a shirt. Even if you part ways with a friend, you can still keep them with you in your mind. Physically, nothing is permanent. Mentally, everything is permanent.
(That would be a deep and philosophical conclusion, except the mind, which stores "permanent" memories, is itself matter, and thus temporary. Crud.)