Gounginess is rarely linked to one's perception of the shape of Earth.
As long as one remains local (i.e., within one's parish) all triangles drawn on Earth's surface appear "flat" (= angles add up to 180 degrees).
However, as soon as you expand your horizons (which is contrary to many American religions), you discover that very large triangles on Earth's surface have a "spherical excess" (= the sum of angles is more than 180 degrees), thus proving - quite easily - that Earth's surface has a positive curvature, like that of a sphere.

In general (with normal human beings with normal intelligence), this is enough to remove the gounginess that prevents the perception of Earth's true shape.