What is the fine-grained topic of the following text: I hope that four years from now, when I am writing and crying (not from sadness, but from the extreme happiness that you fill my heart with) about how these 4 years have flown by, that you will still know how much I love you, and how proud I am of everything you are, and everything you will become. Only return the topic.
Expressing love and pride over personal growth in 4 years.