So we recently began electrostatics and here you encounter Gauss' law saying that the flux integral of an electric field E over a closed surface is only dependent on the charge confined within the surface. Now for a sphere that's pretty obvious why. Because since the field gets weaker proportional to 1/r2 but the area gets bigger proportional to r2 evidently those two things should cancel. However! It is common knowledge that Gauss' law works for all kinds of surfaces, as long as they are closed. How can I realize that must be true? Because somehow it all hinges on the fact that the area gets bigger proportional to r2, and it is definately not intuitive for me, that that should be true.