Yup. Take me for example. I hated Literature when I was in
Secondary School. But somehow fell in love with it during 'A'
Level.
But one thing for sure, till now I still have a strong dislike for
Chemistry and Physics.
Really? I love the physical sciences myself..... 
Anyway, about rap.... Although I admit it's not exactly my cup of
tea, it is in a way, a subset of poetry. I've always seen
songwriting as a special form of poetry. That includes rapping.
Songwriting, however, is much more difficult for you've got to make
string the words into a coherent tune.
True, you've got to harmonize the words in any form of poetry, but
it's much tougher with songwriting.