Often times, our mood depends on what people say or do around us. We react more than we act.
Yoga teaches us that actions themselves are never good or bad. As Srikrishna says in Bhagavad Gita - kaaryate hyavashah karma sarvah prakruti jairgunaih. This means, karma or action happens based on Gunas or Prakruti. People act the way they do, because that is their innate nature.
If we understand this, we will perhaps be more at ease with others around us and react more positively. An action done with this positive and relaxed mind, is yoga.