Just by your being attentive in class your heart is being purified and you are enriching your spiritual life. To help you remember you may want to take notes. For studies you take notes and those nice notes help you remember, so similarly if we cannot remember what we have heard in class we can take notes and go over those notes to help us remember, but just by taking your time to come to the class when you could be doing so many things is purifying your heart even if you dont remember all the details. That is a wonderful benediction.
As far as your studies just try your best and Krishna will bless you.
Lecture: Chetana-Power of Sound Vibration
