Not understanding Storyboard.TargetProperty property

Question

Hello,

What exactly is meant by Storyboard.TargetProperty. I know that it's the property of the object which we want to animate. But why are they so complex like :-

Storyboard.TargetProperty='(Shape.Fill).(SolidColorBrush.Color)'

and why not :-

Storyboard.TargetProperty='Fill'

2nd example :-

 <DoubleAnimationUsingKeyFrames
Storyboard.TargetProperty="(UIElement.RenderTransform).
(TransformGroup.Children)[3].(ScaleTransform.ScaleX)"
Storyboard.TargetName="rectangle">
                <EasingDoubleKeyFrame KeyTime="0:0:1"
Value="1.88"/>
            </DoubleAnimationUsingKeyFrames>

Do i need to remember this strange and complex targetproperty? Any help or any tips and tricks to remember this is appreciated.

Thanks in advance :)