The writing journey can be a very odd one in that yes, sure, you can end up where you thought you wanted to be but it is equally true it can take you to different places. I never envisaged being a short story writer when I first started (yet alone write flash fiction and blog regularly), but am so glad I have ended up where I am now. Yes, I still hope to get my novel out there but I plan to continue to develop the blogging and short story writing as I have "something" here. I want to see where this particular writing road will take me. It seems silly, to say the least, not to do so, but I had to be open to the idea of trying this form of writing in the first place.
So be open to the idea of trying new forms of writing. You never know, you may find at least one "takes off" for you.
It is also true our characters should be open to possibilities in our stories. I find closed mind characters boring to read. To me, there is literally a limit to what they can do. They're a kind of literary one trick pony. I want my characters to be more than that. I want them to grow, expand what they can do and even take me by surprise with what they come out with sometimes. (That last point is a sure fire way to know your characters really do "live"). This is one reason I'm a huge fan of Terry Pratchett's Discworld series. His characters do expand and develop - Vimes is, I think, the best example of this - so of course you want to read the next book to see how they've developed this time.