Have you considered that not paying attention is actually being preoccupied with something that stops you from focusing on what you need to do. This is valuable information I gained when studying with Robbins/Madanes Coach Training.
This may not be you, it may be someone you know who doesn't seem to pay attention. In times of great worry, we focus more on the worry such as lose of security or a sick family member. Some people have a difficult past and worry/stress is part of daily life.
To transform this, firstly you have to ask the question - what are you preoccupied with? Maybe you are preoccupied with singing a song or working out how you will survive. Once you can identify what this is, you can create a strategy to transform this.
Start with giving a dedicated time to worry and journal about what is worrying you. This is your time to focus on the worry. Not any other time of the day. Keep the time for journal no longer than 10 minutes then stop. Get up and move around, then go about your day. You may choose to do this twice a day. By making this an appointment with yourself, you can train your mind, body and emotions to be more attentive.
Admittedly it is easier to do this when you have a mentor or coach to support you. Right now, consider this question and mindfully play with the notion that you or someone you know is actually preoccupied.
Reach out and chat here annaschaumkel.com