Every assumption a person holds presses toward its own fulfillment and will not rest until the outer world matches it. What is called anger here is only that pressure, the refusal of an inner conviction to fade before it has hardened into fact. A belief carried long enough performs itself; the mood becomes the circumstance, and the man meets in his day what he first accepted in himself.
The latter days are simply the moment of arrival, when the thing shows up and the mind looks back and sees the seed it planted. Understanding comes late because the cause was invisible and the effect was loud. The assumption was never idle. It worked the whole time, quietly building the condition he now stands inside.