Everything I've read says that grief isn't something you "get over." Grief from losing someone to death isn't the same as grief from, say, a breakup. The latter you can "get over," but the former you cannot. And it's okay.

As others have posted, grief comes in waves. And, with time, the waves come less frequently, but they don't stop coming.

I do think it's quite impossible for someone who has never lost anyone important to understand grief. It is a completely different experience from anything else.