Question: Is happiness dependent on external factors or solely on the way we see things?
Answer: I would say, both. At the end happiness depends solely on how we see things, since everything we see and sense is through our subjective perception of reality. Thus if we change our perception, viewpoint in the right way, we can change how we see, experience reality around us.
On the other hand in order to change our inherently selfish, egoistic and hateful nature and perception – that gives us the picture, movie of this hostile, dark, self-destructive world – we need external factors, the proper “laboratory conditions”: the perfect, purposeful environment with the right, practical educational method.