There is something about a new setup. You get to start over, clean, void of distractions. The possibilities are endless. That is the part I really enjoy, like many I assume. I recently set up this publishing site, a backend to manage it, a service to backup and secure the data, and on and on. I also setup a physical desk in my house for the first time in 10 plus years. Getting space set up, the monitor just the way I like it. All of this was fun to do.
The opposite of a new setup is - consistency. Coming back to something again and again. Slowly chipping away at the progress until you've achieved something. This is more akin to getting in shape, writing that great american novel you've always talked about. There is a long arduous process involved. For a lot of use it is a constant state of self doubt lows, and small achievement highs.
It will come as no surprise that one of these is vastly more rewarding that the other.