Hi Douglas,
I just finished my college and quite interested in RNNs and fascinated by their capability and potential. Should I go to graduate school to study it or I can play with it as a hobby. Do you have any suggestions?
I think you could play around as a hobby. You might try Theano as a place to start (for LSTM: http://deeplearning.net/tutorial/lstm.html). If you become passionate about neural networks you might find yourself in grad school simply because that's a great place for diving in more deeply. It's really really helpful to know machine learning. Andrew Ng's Coursera is a great place to start: https://www.coursera.org/course/ml