Technically, every paragraph in that poem is very inspirational and motivational, but probably my personal personal favorite, or like the one that I learned from the most was the line or phrase " Be Yourself " and so on after that. That's what I've been doing ever since. It was incredibly rarely that I wasn't myself, it probably only happened during times were I wasn't feeling well (ahahahaha) or probable Sarcasm.
In a way, it does. It makes me realize things that I'm supposed to apply in my life. It is surely helpful today, especially with the people in society being very complicated and complex to identify nowadays, and in the later years to come. The paragraphs of the poem help you realize what is wrong and what you should avoid to have a good life. The poem is a heads-up on matters in your life that you might feel are, off, or are not right
Desiderate (as long as the reader understands the poem) teaches people that there is always something to be positive about despite the overflowing negativity in other peoples lives. It also teaches the reader various improvements for one's self.