Knowing that you received so much from others and this world.
One who can focus his mind on an object during meditation but does not know the true nature of the object is like a camera that can take a photo but does not know what it is taking a photo of.
Check to see if your meditation is making progress or being stuck. In other word, check your practice whether you continue to learn new from your meditation, or not learn anything new from your meditation for weeks, months or even years.
To know what we can not know by thinking.
When you do it in a way that is difficult, it is difficult.
No need to block. Just be with the sound. Alternatively you can use the sound in your meditation.
You are neither responsible nor not responsible. You are not the sole cause of pain in your life. For example, you can make a pizza out of ingredients provided by others and the world. But you can not make a pizza without ingredients, others and the world.