How do I use Proportional Edit Correctly? I've tried everything to fix this. Restarting my computer, closing Blender and opening it again, uninstalling Blender and installing it again. Unless it's a bug, I don't know how to fix this. Advice anyone?

Also here's a screenshot of the issue I'm having.:


I made the mountain after selecting "Spherical Falloff", I'm trying to make a hill, and it's obvious that is no hill.
When the proportional editing tool is activated and being used useful usage information is displayed in the 3D View header.

The tool makes use of the mouse wheel for adjusting the radius of proportional influence, bigger values meaning more proportional movement.