Can depression make you feel numb instead of sad? Is that still depression?

Nobody pictures depression as staring at a wall feeling absolutely nothing — no tears, no darkness, just a gray, hollow emptiness where your feelings used to be.

But numbness is grief too, and a lot of people go undiagnosed because they don't match the picture they were given.

Have you ever felt too empty to even feel sad — and did anyone around you recognize it for what it was, or did it take you a long time to name it yourself?