It's not. Those feelings - the former and the latter are all perfectly normal.
We are created with deep emotions but also with the mechanism to overcome those emotions once they have served their purpose.
Following are a few "myths" about the pain of loss that may be helpful:
MYTH: The pain will go away faster if you ignore it.
Fact: Trying to ignore your pain or keep it from surfacing will only make it worse in the long run. For real healing it is necessary to face your grief and actively deal with it.
MYTH: It’s important to be “be strong” in the face of loss.
Fact: Feeling sad, frightened, or lonely is a normal reaction to loss. Crying doesn’t mean you are weak. You don’t need to “protect” your family or friends by putting on a brave front. Showing your true feelings can help them and you.
MYTH: If you don’t cry, it means you aren’t sorry about the loss.
Fact: Crying is a normal response to sadness, but it’s not the only one. Those who don’t cry may feel the pain just as deeply as others. They may simply have other ways of showing it.
MYTH: Grief should last about a year.
Fact: There is no right or wrong time frame for grieving. How long it takes can differ from person to person.
Source: Center for Grief and Healing