Jack of all trades master of none, I feel is a statement which negates the ability of people having multiple skills. But if we apply it on doing multiple tasks at the same time and then expecting every task to be up to the mark then this statement holds substance. Concentration is an extremely important ingredient in effective learning. All other efforts go in vain when desired level of concentration is not there. Particularly in Level II after experiencing the depth of concepts, I can assure you that concentration while reading is inevitable. A common problem while reading is that rapid thoughts come into the mind and we are distracted from what we are primarily doing. This has been an issue for me when I was doing O'level and A'level. Realizing it as the biggest hurdle in making me improve my learning abilities I somehow learned to converge my energies and restrict those thoughts from entering in to my mind while reading. It is more like a fight which you need to initiate and restrict those rapid thoughts. The moment you are able to control these thoughts and ideas bumping in, you are in a position to manage yourself up and converge your energies on what you are doing. Changing the attitude towards things is a must in this regard. We need to decide whether we want to do one work at a time or do multiple works at the same time and try completing them simultaneously. This is the first decision which we have to make. A simple test to check our 'default status' in this regard, is to see how many tabs we open, while using internet browser, at the same time. I can recall I used to initially open 4,5 tabs simultaneously and when one page used to load I remember switching to the other tab and in this way I wanted to manage multiple tabs at the same time. I realized that this was exactly the same happening to me while reading. I used to finish a line and then start thinking of something else and after that return to the same paragraph and read another line. It took me some time to control myself and focus on one thing at one point of time. This has resulted in a way that I have made myself organized and I try doing one work at a time in the best possible way. I think you should also give it a try and first test yourself how many tabs do you open and gradually limit them up by prioritizing in them. Soon this behaviour would replicate in your studies and you'll see how your performance improves.