For myself, it's all about having fun and getting to share that experience with others. I think I've learned that I will not post videos if I'm not enjoying the entire process. When I started YouTubing, I had very little traffic, but I was enjoying simply making videos for myself to watch. Then all of a sudden I got a lucky break stumbling onto a new game that did well.
For the next 2 years I enjoyed steady growth allowing me to actually earn a bit of money doing something I loved. Around 3 years into the process it started to become more and more like a job. The time between post started increasing exponentially, and before I knew it, YouTube started to become a thing of the past.
It stayed a thing of the past until a couple months ago. I finally found a new game I enjoyed enough to share. That was when the yearning to create content started creeping up in my mind. That lead to a decision to make a new series, so 2 days ago I very reluctantly posted that first video in 2 years and 361 days.
While nervously refreshing the video to read the comments my mood shot straight to cloud 9. The next hour spent interacting with my viewers was pure nirvana. After 3 years away, I have again found why I do YouTube.