Arthur Shopenhouer & Me
How we see the world, touch it, and listen to its voice is through our senses, and they give us thoughts and experiences that become our private, subjective experience. But the underlying processes that run the world cannot be known by us objectively through our senses or mind. It is like being aware of watching a TV screen and of the back-end processes in the software. What we experience is just like watching the screen of TV.
So, from that learning, we can say that everyone experiences the world differently. Another point is that everyone experiences one reality and that subjective reality is the truth for him. Objectively, we can only be aware of time and space, which shape reality. We can argue the opposite: that objective reality exists by creating morals, ethics, and laws, but all of those are our minds' creations, shaped by the world we experience and by our attempts to harmonise it.
Apart from that, we can learn from Schopenhauer that, in this way of learning, we get only the representation of the world.
Another point he makes is that we always try to change the world by wanting things. This is common to living and non-living things. Plants want more water, and humans want more power and money; these are just different types of wants, in different proportions.
To live happily, we just have to understand that what we get is beyond our senses, and we can, as humans, be aware of it, control our reactions, and choose how the mind responds to it. Secondly, if we become aware of the wanting instinct, we can choose what we should really want to have a more satisfying life for us as well as for society.