Why did we put this elephant god Ganapathi on top a mouse?

Mouse is a very interesting rodent that can hide anywhere, come out from anywhere, at the most unpredictable time, multiplies easily and can create havoc.  Problems in lives are like that.  Mouse is symbolic of those problems in life, which can come from anywhere, anytime in the most unexpected manners.  And when that happens, the only way to overcome these problems is through our brain.  To symbolically represent this, is why/how they represented Ganapathi (who stands for the brain) is made to sit, control and conquer the mouse (which indicates problems in life).