So whatcha whatcha whatcha want?
Back in the day when dinosaurs walked the earth and I was starting to play RPGs, our characters had pretty simple desires. Kill things, take their stuff and stay alive. Save the village. Collect the reward. Become somebody. Build a castle and retire. Complete the quest.
The monsters and non player characters had fairly straightforward motivations as well. Kill the player characters, eat the player characters. Take over the world. Do the evil thing. Keep their stuff. Cut and dry.
There’s nothing wrong with those types of motivations in certain games and cultures of play. However, many RPGs include or even focus upon the motivations of the player characters to a lesser or greater degree. What does your character want? What are they willing to do in order to get it? Some games are all about what the characters want, while other games have more of a backdrop where the desires of the PCs inform how they act as the world keeps turning.
NPCs are people too, (sometimes) and they can have the same range of wants, desires, and motivations as the player characters. NPC actions become quite intuitive once you know what makes them tick.
It’s been my experience that gaming can be much richer when you know what the characters want. It’s a vital step to making them real people within the setting and within the fiction. Even more satisfying is when they have conflicting desires. Choices become much more (dare I say realistic) when characters have warring motivations within themselves, just like we do. They certainly won’t be flat and two dimensional.
As Veruca Salt said, “I want it now.” ~ Are you gonna tell he she can’t have it? I’m not.