As human beings we seem to be attracted to dualism in one form or another. The notion that two parts or aspects form a greater whole appears to be instinctive. Some of these variations seem reasonable while others are far more speculative and ungrounded. One variation that I have always found to be more interesting and reasonable revolves around our sense of self.
Most of us are caught between two points of view that, at least superficially, seem to be at odds. Most individuals want to think of themselves as unique. In many ways this is true. We have a variety of traits/characteristics that makes us distinguishable from any other person we meet. We are individuals. Yet, we are also all human. We are part of a distinct species with a variety of overlapping/common traits. Most of us also want to be part of a greater whole. We want to fit in in some way. We want to be special and simultaneously alike. How can that be?
Personally, I think it is reasonable and not nearly as contradictory as it first appears. We are sentient socially driven animals. Like all primates we have a strong instinctive drive to favor social interaction. We do not do well in isolation. This is not to say that we can not function on our own for long periods of time. However, a variety of experiments and observations have confirmed over the centuries that the longer an individual is deprived of social interaction the worse their mental and physical health becomes. We are also conscious beings. We are aware of ourselves and others in ways no other species are (or at least as far as we can confirm at this point). Being able to distinguish our selves, the self, is a useful adaptation. One practical example of this melding of self and community is the "Division of Labor." We hear a lot about how culture evolved and impacted human biological evolution but one aspect that usually does not get nearly enough attention is the Division of Labor. Thinking about how we work together for both personal and communal gains is an excellent way to frame this seeming contradiction of perspectives.
In the end I cannot fully explain this type of duality. Perhaps we will never understand it or the components that seem to contribute to it. It is still quite interesting to ponder. Self and consciousness are each topics well worth exploring in and of themselves. Throw in the impact they have on a variety of other topics and concepts and you have multiple life-times worth of questions.