During the grieving process, you may go through phases of feeling unmotivated, frustrated, or other such emotions and feelings. Because the whole grief-comes-in-waves thing wasn't enough. This list doesn't exactly follow the five stages of grief, or even the seven stages; it's somewhat of a modified version.
Now, everyone grieves differently, so the process will vary. A person won't necessarily go through these in the order I've written them, or do them one at a time. They can hit multiple things at once, and wield the negativity with great... uh, disaster.