I didn't have any sense of myself until I met them.
The universe is made of two things. An infinite space and objects that live in it.
Like the universe, we are an unlimited space in which thoughts and feelings (objects) appear.
When we identify with our thoughts and feelings, we reduce the ocean of ourselves to the creatures that live in it. We do not know ourselves beyond our mental state. The self is confused with the mind.
When we are being told that we are wrong, our sense of self is suddenly being endangered. This is where the ego becomes defensive. Especially because the ego always feels like we are just not enough. It always needs more. More things to feel better, more time to be better.
Not knowing what we are beyond our mind or identifying completely with the mind, is the perfect ground for conflict. The egoistic sense of self needs dramas, enemies, difficult situations, to make sure the self does exist, still. It will find any excuse to show how big the self is. It defines its identity through the opposition of the other. "Us against them". It fights in the service of an identity, that is completly built in opposition to the... other.
The ego needs conflicts. Because with no conflict or enemies, the sense of the self becomes so fluid, that it might realise, that we are in fact, just one.