I have yet to read Paper Towns but I really like this John Green quote. Imagining things is what gives us hopes and dreams. It allows us to see what we could do and gives us reasons to keep moving forward. Having active imaginations is something that should not be limited to childhood. Being able to come up with a picture or scenario in our minds can help us reach goals by constantly reminding us what we're striving for or what we are capable of.
Lately I've been trying harder to use my imagination in positive rather than negative ways. In the last few years I have spent more time thinking of all the things that could go wrong in my life rather than what could go right. Those negative images not only effect my anxiety level daily, but have hindered progress in certain areas of my life. Picturing myself with an enjoyable job, a gorgeous apartment (that I decorated myself), and a husband I love, instantly makes me feel better about my future. Of course I don't know if all of that is in the cards for my future, but I figure it will make me happier in the present than worrying about the alternatives.
So imagine all the good things because nothing will happen if you don't.