Every character wants something. It's our job as writers, to keep it away from them.
Not forever. If we're good, we string it out over the course of a book or a series, with enough of an interesting journey to keep people reading. We throw obstacles in the way, make them struggle against evil forces, help them grow into the person that can overcome it all to succeed in the end.
But what if their worst enemy, turns out to be themselves?
Say your main character wants to be a fighter pilot. She makes models of planes, reads every book she can get her hands on about fighter jets, joins the air force...but is scared to fly.
What if your character desperately wants friends. She finally finds a group of girls to hang out with, people who seem to really like her, and then she ends up betraying the very person that brought her into the group...
Or maybe your character is a writer. He blogs, he tweets, he's friended every editor on Facebook. But he never has the guts to query a novel. Maybe he never finishes writing one...
What flaws in your character keeps him or her from achieving their goals?