I've just finished the first draft of a short story.
Originally, I had a 24 year old man coming home from a year of travelling to find his mother has just died. A couple of days later and this man is now 19 and housebound. How does that happen? I have no idea.
My ideas form so subtly that it takes a while - musing on the bus, or while trying to get to sleep - for the actual characters to form. When I started writing the 24 year old version, the words plodded along - there was a lot of conversation, a lot of catching up with old friends and family, and a brand new niece, but not a lot was happening. I'd hoped the mother would become important, but I just couldn't bring her to the fore.
Then suddenly, I started again. New, blank piece of paper, and the 19 year old sprung out and steered the story with his snide apathy, quite unlike the amiable character I'd assumed for him. Now he's chain-smoking and argumentative despite the fact he's reliant on people to help him move around the house. Oh, and the mother is now missing, not dead.
Essentially, it's still the same very vague idea of familial relationships. Practically, it's totally different. I love writing!!