As the title states, there are various brief thoughts Epictetus teaches in this chapter.
The first one could be summed up as: stand on your own two feet! Epictetus notes that bad singers are masked when they are in a choir. But if they were to sing by themselves, it would be apparent they are a bad singer. Therefore, "sing" by yourself; "stand" on your own without any help to see what you lack. And by identifying your weak points, you may take action to become stronger.
"If you're anyone at all, man, walk around on your own ... Put up with being laughed at on occasion; look around you, and give yourself a good shaking to find out who you really are" (v. 1-3, p. 170).
Marcus Aurelius shared a similar sentiment when he said, "Your duty is to stand straight - not held straight." (Meditations 3.5)
The next thought regards performing some act which has benefit to you ... and so you do it for the sake of the benefit. Other people might perform the same act not only for the benefit, but also to brag. Today's modern example might be people who brag and talk about being vegan all the time, instead of simply being vegan and letting the results speak for themselves.
"When someone drinks water alone, or adopts some other ascetic practice, he seizes every opportunity to tell everyone, 'I drink nothing but water.' ... Man, if it brings you any benefit to drink it, then drink it; otherwise you're acting in a ridiculous fashion" (v. 4-5, p. 170).
The third thought: two things need to "be rooted out from human beings: presumption and lack of confidence" (v. 8, p. 171).
Don't presume that you know everything and that there is nothing else to learn. Rather, you should embrace a learning mindset. Look for ways to improve your character and grow your knowledge. Be humble in your quest of self-knowledge and learning.
Secondly, don't take the perspective that since there is so much chaos and adversity in the world, it's useless to try to change it. Rather, take the perspective of "growing where you're planted" and try to make your spot-of-the-world a better place. Fight the apathy and the mindset that you can't make a difference.
The last thought from this chapter deals with what you ought to focus on as a human being. Thinking yourself better than others because of your title or your lot in life is not "right thinking." This would be similar to horses bragging about the food they get or the place they sleep. The only thing that matters in the world of race horses is the result of the race - that is the ultimate measure of a horse.
For humans, the ultimate measure is virtue. If you have courage, justice, temperance and wisdom, then you are succeeding. What your lot in life is, the condition of your health or size of your bank account mean nothing if you don't have a good soul - a good character. "Show yourself to be better in these [virtues] so that you may be better as a human being" (v. 14, p. 171).