Cherish everything you have because not everyone has them. An item is something unique that's why people parents always tell them to take care of it.
Don't mess with fate, the theme of the story, is what the author is trying to tell us. Wishing for something will lead to something good or bad which leads into messing with fate.
If you want something you have to earn it and work for it. It's like the saying hard work pays for everything you want.