Each person's lived experience is the most important thing. Having said that, we all theorise, whether we are aware of it or not. We all try to understand things, to connect events, to build models of how reality works. Looking at theory can help us to see other possibilities, to free ourselves from oppressive ideas and what's more, to challenge those people and social structures which oppress us. Postmodernism can be a bit difficult to get to grips with, because it sees everything as being relative, in other words there are no ultimate truths or realities and everything is made up by all of us in interaction with each other.
Reality is seen as being fluid, multilayered, contradictory and full of irony.
Perhaps particularly the varied experiences of transsexual people in transition, intersex people and transvestites. And in terms of society, one can argue that 'man' and 'woman' as the 'only way to be' are made-up terms anyway. It's just that everyone takes them for granted to the extent that they actually believe they are real and that everything which does not fit is somehow 'wrong' or 'sick'. But it does not need to be that way. Getting back to people's needs and experiences brings one slap bang up against the realities of the human need for an identity which works and which makes sense in the world around one.