Grief is a fairly mysterious concept for many people. Sit in on any of the local grief support groups and you are likely to hear at least one person ask if a particular response is normal. A just as likely response is that “Everyone grieves differently”. Hardly the definitive answer many are looking for, but basically true.
As adults, we perceive—whether it is true or not—that we should not be having feelings of sadness and loss after an arbitrary time limit. Intense sadness and loss should pass in a relatively short amount of time—or so some think. The truth is that the feelings of loss generally do get less intense over the passage of time along with a healthy support system. However, even with that there will still be moments/days where we re-experience things when we hear a particular song or see something that reminds us of our loved one, or on certain anniversaries or life milestones, and a negative change in mood is a normal response.
Grief that does not improve over time, despite a healthy support system, is more of a concern—especially if there is a loss of hope. In these situations, meeting with a therapist is a good first step.