In fact, time is something that can give us our best excuse for NOT doing something that matters to us. (See "challenges" below.) In order for us to have a 'body of work', we had to make room for actually making it in our lives.
We chose our medium(s).
This may seem like a no-brainer, but it isn't. Some people choose their art medium because of the automatic respect they believe they'll get from it (like oil paints over acrylic, for example.) That's okay. But in fact, most of us choose our medium because of how it meshes with our own personal habits, quirks, and preferences.
Each medium has its costs, drawbacks, and benefits, each forces us to interact differently with it. I quickly grew frustrated in my one acrylic painting class, because the paint dried too fast. I couldn't play around with it, blend it, etc.
I can't even imagine working with watercolor! Knowing our work preferences and process helps us see our works-in-progress more clearly.
We know our materials.
We know what substrates (canvas, paper, wood panels, for example) will work best with which media, and how to prepare them. We know which glue to use with what (and if we don't, we know how to find out!)
We've learned what color blending techniques to use, how to construct an effective color palette, what kind of clay to use in our potter, what glazes to use, how long to fire polymer clay, what our preferred method of book-binding is, etc.
We know our process.
In my own box art path, I've learned that epoxy and silicon construction glues can be very useful in putting several boxes together. But they have their drawbacks, too.
I used them until they didn't work for me (e.g. in some cases, the glue bond is stronger than the old wood I'm attaching it too. Ask me how I know.) Then I had to try something else.
We have experience with solving problems.
So many of us (ME!!) forget this. We've gotten used to success with what we've learned. We forget how hard it was when we started out.