I find it interesting as a new writer to see how I handle a block, or a flow that departs from the planned direction.
As a reader, you do not know what is on the next page until you read it. As a writer I often do not know what will appear until my fingers follow my imagination! Sometimes I am as surprised as you are!
I am fortunate in that my mind allows me to create and craft a story as I am typing, sometimes ending up with plot and dialogue I had not planned at all.
That is how some humor ended up in NYC. Just by letting the conversation go it's natural course without trying to craft it. In other words, I'm reading the story as I type at probably the same rate of discovery as you when you read the story. Sometimes I manage 5000 words a sitting in this way.
Let me know, how you find unexpected additions to what you write?