There is one thing that can hold my interest longer than a really exciting project. That thing is people.
The creative process is engaging and exhilarating. Any good work of art conveys a message and elicits and emotional response. But people (even the most boring) are full of messages and stories, and each one is capable of a dynamic range of emotions far greater than any single work can encompass. Every interaction with another human being is like sharing a great work of nature. People are awesome.
Artists take part of the world and shape it, creating something new. But the experience of creating a work also shapes the artist. Likewise, every single person affects the experience of the people around them, and too is affected by others. We are all artists.