Ever known that person who can't sit still, seems detached from the present moment, and won't just chill out and relax? Someone who complains all the time? You could say a person like that is dissatisfied. And you could also be describing the speaker of "Keeping Things Whole." He's dissatisfied, but in a different sense—he doesn't have a feeling of emptiness, he is the emptiness, and his eerie descriptions of how that manifests in the world creates a feeling of dissatisfaction with himself and his existence, which keeps him moving throughout the whole poem.
Imagine trying to fill a bowl full of holes with water and you'll get an idea of how unsatisfied the speaker feels about existing in the world.
The Rolling Stones had it right when they played "You Can't Always Get What You Want," and for the speaker, it seems that he's motivated to move through the world by a feeling of never being able to get a sense of who he really is. That's what he wants, and he's never gonna get it.