Pre-taking medication, here's what my personal experience trying to focusing looks like:

I have some really interesting, but lengthy text that's really important for me to read for class. No cell phone, cleaned my room, put on specialized focus music, jot down all my random thoughts on a notepad, got myself a cup of coffee and made sure I eliminated all distractions.

I then proceed to read the first two or three sentences before I realized I have been mindlessly scanning the text with my eyes like I'm reading, but instead I am doing the equivalent of watching a movie. I'm 100% zoned out and in la la land.

I realize this, so I stop, refocus, repeat. I realize I did it again, stop, refocus and try reading out loud. I'm annoyed because I'm saying the words out loud but not comprehending it.

I meditate for 30 seconds to calm my mind, try to refocus and repeat. I finally get through it after about 30 minutes.

Here's how my personal experience looks with medication:

I pick up the damn paper, read it and summarize it with notes in 5 minutes.