The grid is mainly for you to line up and take your photo straight, not crooked. How often have you taken a photo only to realize you were holding the camera at an angle? The grid helps you prevent this.
The above poster is referring to the 1/3-2/3 golden point... if your main subject is at one of the "third" lines (either left one or right one), it will be visually aesthetic. This is from art theory, as applied to photography.
And a PS - the only stupid question is one you didn't ask.