We often don’t need to see to know how to get the food into our mouths because we’ve been doing it for a long time and we’re familiar with the process.
We also don’t need help getting around our house, the map is already stored in our minds. It appears we don’t need help on doing things we’re familiar with but there’s an exception which is knowing yourself. We often need to talk to people to see ourselves better, people help point to certain biases and influences that we don’t even know exists. Being familiar with ourselves helps but it doesn’t guarantee accurate knowledge.