I'm interested in the concept of "epistemic privilege" - the idea that those who are marginalised occupy a position of privilege in terms of understanding "how the world works".
I'm not sure who first used this particular expression, but it probably originated in Marx's claim that the ruling ideas of any historical period are those of the ruling class. This starting point has been elaborated into "standpoint theory" (e.g. by Nancy Hartstock, Sandra Harding), which focuses beyond class to looking at marginalised people and their (our) exclusion from the construction of knowledge. Harding argues that marginalised people are in a privileged position to access "objective truth" (she writes about science), because marginalized groups learn the dominant viewpoint while experiencing its limitations, and hence are in the best position to see its limitations. This certainly resonates with my experience, especially in the context of mental health diagnosis.
Of course, this idea must be elaborated to explore complexities, e.g. (i) how far does epistemic privilege extend? e.g. do marginalised people have a privileged understanding of phenomena beyond the specificities of their marginalisation (e.g. of "science" as Harding claims)? (ii) surely men can come to understand relations of sexism, or does their position of privilege intrinsically preclude their understanding? (iii) how do multiple axes of marginalisation intersect? (iv) is it intrinsic to the positioning, or does one have to have "class consciousness" to have access to epistemic privilege? - I know Marx has ideas on this, but I haven't read any Marx.
While this idea could be problematic if it essentialises or reifies the centre/margin distinction, there's definitely something to it. Like all operations of privilege, it has to encompass plurality and diversity (without losing sight of hierarchical relations within diversity).
Also, to finish off, here's a passage from Said's work (the guy who wrote Orientalism and inspired postcolonialism as an intellectual enterprise). I think this captures the relationship between personal experience and political ideas:
"There is therefore this quite complicated mix between the private and public worlds, my own history, values, writing and positions as they derive from my experiences, on the one hand, and on the other hand, how these enter into the social world where people debate and make decisions about war and freedom and justice." (Representations of the Intellectual, 1994:9)