It's a good anecdote but needs a bit more boundary condition. One can always pick a level of abstraction to make an explanation long or short; humans usually pick this level based on context and social convention. For example, if the question was "describe how a keypress results in a screen glyph" can be described in one sentence, or in a long series of books (assuming you get into the firmware, software stack, electronics and materials science, manufacturing processes, etc). For WW2 you could say it started when Hitler invaded Poland, and then France. Or you could get into the Versailles treaty. Or you could talk about the evolution of life on Earth. You might say the latter is pedantic, and it is, but it's also technically an event that led to WW2.
