Even if you pull an “all-nighter” studying, test results from junior and high schools students have shown terrible results. Without sleep, it becomes difficult to remember things as the knowledge has not had time to settle in.
So, why is it so difficult to remember what you studied? This is due to the lack of sleep, because the brain works even while sleeping to establish what you have studied. So, even if you study desperately by cutting into your sleep time, it is a waste of time and effort.
Another reason is that there is no time for the brain to remember by repetition. Repeated learning is important to establish memory and memories that have not been repeatedly learned are quickly forgotten.
There is no easy shortcut to get results from studying. It means that you have to sleep well and study every day.