What motivates you to do stuff....like i don't know writing a story or doing some other thing

3018854 you can find motivation from several things like a story about a TV show you liked or a really good video game.

3019908
But how can I use that to my advantage

Passion is the key. That, and free time. If you have free time but don't write, then you may not have passion for writing. If you have passion for writing but don't write, then you probably don't have free time.

For me personally, I am motivated by a love of story and imagination. I can hardly listen to any song without envision what it would look like in my head. And oftentimes, that vision will become a story. I don't write very much at the moment, however, due to attending college and working a part-time job. I love to write, but simply lack the spare time.

3018854
Random thoughts in my head. Depends on the situation.
Dire Strait's "Money for Nothing" caused me to write an literary adaption of it.
I was playing The Last of Us, Battlefield 3 and GTA V while I was writing a fic about Button Mash seeing video game characters in real life.

3020384 it really depends on how you use that.
think about what you could get from a good story, fame, people who would listen to you and the satisfaction you get from a complete story is like building a computer and it actually works.

Lonly Brony has the right idea, I believe it was Sigmund Freud that said that pleasure was what drove us to do anything. Out minds say tell us what will bring us pleasure, and if out ego allows it, then we do it. The super ego, which is created through society, also influences out pleasure, as it creates society morals. This was one of the main ideas behind rapture, as without society's morals, we would be more inclued to push the envelope and think more on logic than morals.