Question

Why might a student be proud if he or she memorized a famous speech

Answer 1

Because when someone memorizes something, it is most likely going to be hard to memorize, and when he or she accomplishes it he/she feels that they did something great, and since it is a famous speech, that means that what he memorized is important.

Answer 2

She would be happy for memorizing it.  Because if someone might ask a question about it or anything related to it that student will know.