M is for...

 ...the midway point...wow, already...how we all doing...still here???

...Motivation, as in what are your characters needs and wants, what keeps them going through the story?

Motivation is very important to your characters, it's what keeps them going through the story and should be decided early in their creation. Motivation is the underlying reason that the character has a goal, like the need for self preservation. 

Motivation is behind everything that your character does, wants and needs. Just like in real life, your character wants something, and to get that something they have set goals, and keep moving forward to achieve them. 

Real life people will eat because they are hungry, they will take a job to pay the bills, and gain financial security, they will look for a relationship because they think they need the emotional intimacy of another human being. Feeling mad at someone, or feeling 'off' will keep us away from a person, and if a person wants a better home, or car they will go after a promotion. The same thing should be true for your character, what are they in the story for? What the heck do they want?

Again while the reader may never be told this, it should be evident in your story, their motivations should help you the author write the book, as you will know how they would react in any given situation and why.

Physiological: These are actual necessities of life, like food, water, sleep, etc.

Safety: Though not quite as urgent as the physiological needs, security, health, shelter, employment, etc. all fall into this category, and are high on the list of priorities.

Belonging: Anything to do with a relationship, particularly of the non-sexual kind (though that is included) goes here.

Esteem: Motivations of esteem make us strive for confidence, achievement, the respect of others, etc.

Self-actualization: Finally, last on the list are needs like morality, creativity, and other things we might consider indulgences if the other needs are not met, but are still important to us.

These can be then shortened to:

Basic Needs (physiological and safety/security)

Psychological Needs (love, relationships, belonging, esteem)

Self-fulfilment (self-actualization and creativity)

Try out this site for help figuring out motivations:

Character Motivation Thesaurus | One Stop For Writers

50 Character Goals (With Character Motivation!) | BRYN DONOVAN