Writing the Future?

Merry Meet.

I love writing.  It is one of my past times just like art.  But when I really focus on a story, usually never finished and very short, some of the events start happening.  They may not be the exact events written on my paper, but they main idea happens in one way or another.  For example, I had written once when I was 13 that one of my characters (whom was based off me) recieved a laptop for her fourteenth Christmas.  When I was 14 and Christmas came around, I recieved a friend's old laptop! 

There is a catch, if it can even be called that. I cannot write whenever I want and I cannot write out specific events for people.  Once, my friend Chous had asked me to write the day when he found his true love and in the middle of writing it, I had fallen asleep.  I got as far as writing that he had just recieved a letter that I was not allowed to see and I was stuck there because I didn't know what the letter said!. 

Is this ability really possible?