What does it mean to take responsibility for one's own feelings, and why is doing that important for successful communication?

Taking responsibility for ones feelings means you understand yourself better and will help you become more confident once you are comfortable enough in your skin and being confident helps with communication skills

Because without physical activity, the body has extra "energy" if you will, and so when it is time for bed you are not tired, so you end up staying up all night. also there is probably an effect on your internal clock, which messes with your melatonin production which goes hand in hand with your sleep cycle