Tl;dr Just down vote me.
Motivation. It's a consistent post here: How do I get it? What are some tips to obtain it? Why don't I have it? And for some reason, this sub has some alcoholics-anonymous levels of dedication to supporting people struggling with it. But, I'm going to be brutally honest and blunt when speaking about it. I don't expect to get upvotes for this; I expect everyone to hate me. But I need to tell my truth.
I recently inquired on some forums with similar questions about motivation from different aspects. It started with Reddit, but as I didn't get a huge data set, I moved on to other places. But, even with the few responses I got, the message was quite clear: If it's a hobby, and you're not feeling motivated, try a different hobby. In other words, if you can't seem to motivate yourself to play video games or watch TV, try something else. "Maybe you're burned out." "You might find that a different hobby is better for you." "I found that depression was the reason I could no longer do ___ hobby."
When it wasn't a hobby, but something good for you–work, exercise, home cooking–they had similar responses to people on this forum: listen to music, power through, think of the future or outcome. Working out was specifically something I saw compared to writing recently. The motivation–or reason–is to be healthy, fit, attractive, but actually working out is work. But if you're motivated, a benefit will be had. Writing is work, so I understand the sentiment, but on the flip side, quoting many people on this forum about trying to make money: you shouldn't. If you write for enjoyment, with no worry in mind, it shouldn't be like work. You should be doing it because you love it. A paycheck is just a bonus.
My point is this: If you write because you love it, then motivation shouldn't be a problem. You write for enjoyment, entertainment. You love creating worlds. You love putting yourself in someone's shoes. If you're doing it for money you may want to reconsider. This is not a hobby that often turns into a profession–not a profitable one, anyway. Much like most arts, people work shitty jobs hoping for the day that they make it, and most of them end up stuck waiting those tables or fixing those cars for the rest of their lives.
I've been motivated to do things I didn't love to earn money. I've been motivated by need and responsibility. But when it comes to writing, I've only ever been motivated by enjoyment. I love it. I stopped playing video games because I love writing far more. I stopped watching TV because I love writing far more. And whether or not I get paid for doing it, I will continue to pluck away at a keyboard until late into the night–late into my years–because I love it. "I'm still in love with what I do, making things up, so hours when I write feel like very blessed hours to me." –Stephen King.
So here's my my karma coup de grace:
If you don't love it, can't write, don't write, find what you love and let it kill you. –Kinky Friedman
Even if that means it isn't writing.