In the beginning of the movie, Shrek is seen as a monster. Most people are afraid of him and judge him based on his looks. He copes with this reality by isolating himself to his swamp and by playing into those sterotypes by scaring mobs.
When Donkey refused to leave Shrek alone, Shrek finally opens up. In this scene he is describing how Ogres are not simple beings, they have emotions, feelings, and motivations. This is the beginning of his emotional and phyiscal journey where he finds a sense of belonging.
The movie ends with Shrek and Fiona expressing their love for each other, while Donkey saves them from Farquad. Viewers find out that Shrek is capable of true love and that it does not matter what someone looks like. Shrek is then surrounded by his new family that love him.