Character Motivation
On this writing journey, one of the things I struggle the most with is GMC: Goals, Motivation, and Conflict. Actually, establishing a character's goal(s) is the easiest part. Motivation comes harder.
Motivation is the driving force behind the goals. Why does the character want this goal? Just about any goal is possible as long as you help your reader understand why the character does what he does, why he makes the choices he makes. The character must have compelling reasons for every action he takes. As the writer, you must show the character will walk into danger because he has no other choice. The motivation must be urgent, or no one will care.
The motivation must make sense. Too often, writers have their characters making choices that just make the character TSTL (Too Stupid To Live). And, remember, the characters are people. People generally will take the easiest action available to them. So, in order to get out of a burning building, if a character has the choice of merely walking through the front door or climbing up a ladder, across a beam, and jumping out of a second story window, you'd better have a compelling reason for the character to not escape via the front door.
It's just like in a horror movie (which I've been watching quite a few of here lately. Yay Halloween!). Everyone in the audience knows the monster is in the basement, yet there goes the hero down the stairs. How often have you found yourself yelling at the TV screen, "No! Don't go down there!"? Probably as frequently as I have. If the hero is going down there and you don't know why, he's TSTL. But... if the heroine is down there, or the hero's brother, then he has a compelling reason to go where everyone knows the monster is. Instead of rooting for the monster (because the dummy hero deserves to die if he goes down there), you're on edge for the hero, wondering how he's going to triumph over evil.
Writing isn't easy. It's a mixture of creativity and logic that sometimes defies description. But, done right, it's a beautiful thing.