What we study is only for a certificate most of the times. Whatever we going to apply in the actual working environment is really from on job learning and continuously improving our knowledge.
This is not just in studies. In life, we are always learning, be it in your hobbies, in family relationship, in workplace etc. We are always learning to manage our own life. In studies, I feel that most importantly is follow your interests. Ask yourself, is that what you wan to study and does it makes u motivated to study.
I had my experiences after my 'O's whereby I defy all my family and relative decision to ask me study commerce in JC (in my days still got commerce) to study engineering in poly. I felt that I had more interest and confidence doing what i think i will do best and i will go all out to do it.
So really most importantly, u must be interested in what you are doing. Adapt and be flexible in your approach to things.