This may seem like a silly question and the answer obvious, one word at a time, but seriously how does one write a novel?

Having grown up and written in the digital age, my brain is hardwired for short bursts of information. While I consume novels, I've never actually written anything, aside from a research paper, over 10,000 words. 

So I wonder how do you reprogram yourself to think in novel terms? Full story arches, character composition and entirely created settings? Do you break out a whiteboard and plan the entire thing?

While my attention span isn't completely shot, I am finding it difficult to stay focused long enough to write for the long haul.

Am I the only one having (or has had) this issue? How did you transition from shorter forms to writing a novel?