American Gods by Neil Gaiman. I was in second year of my graduate program, stressed as hell due to final exams and papers all falling within 4 days of one another in the lead up to winter semester break. To make things even worse, I had left my dog with my parents in a different province and not only had I spent the whole semester missing him, but my mental health had greatly suffered in the previous months without him.

About three weeks from the end of finals, I was in the campus bookstore, trying to keep focus and look past finals and exams to getting on the plane and going home to see my dog (I mean, my family) for Christmas break. Came across American Gods and bought it on a whim. It was the first book I'd bought since starting my grad program (and being a poor student) since I didn't have time to read novels, so it was a big deal. I kept it on my desk as my emotional touchstone, and every time I started to lag or have a meltdown, I promised myself that once this awful term was done, I was going to read that book on the plane home for Christmas.

And that's what I did. I got on the plane, flipped open the book I'd been staring at for three weeks. And what a book! I only got about halfway through it before the plane landed. It was a great Christmas, I got to spend so much time with my dog and recover from school, and finished the book throughout the holidays. Now I every time I see the book on my book shelf, I relive the experience of all the stress literally melting off and the joyous anticipation of seeing my dog again at Christmas.