Nothing makes me sadder than to see untapped potential, be it in the gym or the classroom. If you stop and look around in any typical gym, it's obvious that a good number of people just aren't pushing themselves hard enough. At the end of the day it doesn't matter which exercises you do or how great your form is or how many sets you perform. If you're not training hard enough in the gym none of these other factors are going to make any difference to your bottom line results. Muscle growth is basically an adaptive response to stress. It's the result of challenging your body's existing strength capacity. If you're not performing your sets close enough to muscular failure, your body will not have any incentive to put on new muscle mass. So if you really want to put on some significant muscle size, you need to buckle down and take every set seriously.
Likewise in the classroom. Every semester I am so disappointed by those students who fail to live up to their potential. I'm not talking about students who run into mid-semester challenges such as the death of a family member or a significant health challenge. I'm talking about those students who simply fail to put in the work required to come out with a good grade in the class. They fail to do the memory work and to adequately prepare for the quizzes and exams. It's not a matter of lacking good study habits or time management skills. It's a matter of simply being too lazy to do what is required.
Friend: Waste no potential!