the easy way to explain polar moment of inertia by example (made the most sense to me):
High Rotational Inertia: Take a 10lb dumbbell in each hand and hold the weights out away from your body to each side (you will look like a letter T)...spin in a circle at a moderate pace and then stop as fast as you can
Low Rotational Inertia: Next hold the dumbbell in as close as you can (you will look like you have chicken wings)...repeat the spinning process and stop as fast as you can
Notice the 2nd method (if done right) is much easier to stop...this is what a car feels when you are drifting or purposely trying to rotate the car for the maximum exit speed out of a corner