Why does Unity think this mesh has more vertices than I think it does?

Consider the simple mesh shown in the attached image.

The Unity Inspector is telling me that mesh has 33 verts. I see 12 verts, and my modeling package confirms the same (that is, there aren't any hidden duplicates).

I see inflated vert counts in Unity on most of the meshes in our game, and our overall scene vert count is waaaay too high right now. When I see Unity thinking a mesh has almost 3x as many verts as it actually has, I start getting suspicious.

Anyone know what might be going on here?

 

Vertices must be split on UV and normal seams. The value in Unity is correct.

--Eric

 

Make that same object have only one smoothing group and import back into Unity.
The vert count will then read 12 - until you add lights.