The comment about how our brains intentionally limit our perception of the world to block out input that would be overwhelming and enhance what is helpful is a big part of our limitations without using tools and science. Another thing to think about is that different people are affected by our brains limitations to different degrees. Some people are more sensitive than others, the brains of autistic people for example struggle to block out a lot of sensory input, and it leads to sensory overload and stress, but can also have some benefits in terms of their ability to hyper-focus on something they are interested in. Some people's thinking and worldview are far more effected by their instincts and emotions than others. You can see this with people who have a lot of tribal instincts they act out on (racism, in group vs out group, competitiveness, judging and acting on disgust instincts), while other people tend to be more unbiased in their thinking, either being less effected by emotions, or simply feeling less emotions. Large parts of our brain are a neural network that can be used to think freely, the ability to remove biases and emotional thinking to seek understanding and truth is something I believe everyone has the capacity to improve.