There is a particular skill, which if we learn to tolerate, we can become far more productive than we are. That skill is the ability to tolerate boredom.
When you work, your mind tends to be one-pointed. Over time, your mind starts to go from one-pointed to scattered. It starts to think about random things, which breaks your concentration. However back in the day, if you were in a library and your mind starts to wander, you’d sit there and after a while, your mind would naturally coalesce back into a one-pointed mind. Then you’re focused on your work again
The process of studying involves your mind going back and forth between the states of focused and scattered. On good days, the periods of focus would be longer than the periods of scattering. Caffeine can help this process. This process also involves dharana and pratyahara.