In my student days and even in the office I had no problem concentrating, I could isolate all the outside noise and concentrate on my tasks. It was impressive how I could spend hours advancing in a task, to the point that time would vanish and when I realized it, it was time to go home.
The strategy I used was to pay attention only to what I was interested in, the rest I put in the background.
But now I confess that I do get distracted frequently and one of my goals for 2023 is to get organized and focus on one task at a time. It happens that when I was a student, a cell phone was not a common device, not even the internet, so the distraction was less. In the office, I had so much work, that I had no choice, if I wanted to accomplish my tasks, I had to work hard and not get distracted.
Now that my workload is much less and I am more connected to Internet activities, I find myself trying to attend to everything at the same time, so I understand that your advice is valuable.
The first thing I am practicing these days, is to set a timer to finish whatever I have set for myself, in a reasonable amount of time, I think it might work, because I force myself to stay focused on what I am doing in order to accomplish my goal.
Greetings.