Unity Stats says my 1 triangle mesh is made out of 500 triangles.

Hello guys, I want to make a 2D destructable level out of meshes which I create and handle in code. However by just creating the level my fps is dying.

I tested the thing with only one self-made triangle and thats the result:

Here is my custom made mesh in the Inspector: And here you can see that little triangle and the stats: (no, there aren't other meshes and if I create a mesh with 10 000 tris, the stats says there are 2 000 000 tris)