Example 1
The powerful wizard turned my little brother into a parakeet.
If your little brother is anything like our little brother, then he probably had it coming, and you owe that wizard a gift basket or something. Here, wizard and all of the adjectives that describe him (the and powerful) form the complete subject.
Example 3
Emile hates split pea soup.
Who doesn't? It looks like boogers and its name sounds like a bodily function. In this sentence, our hero—Emile—is the complete subject because there aren't any additional words that describe him.