"Everyone is just like me" - The core unexamined assumption of leftism

Samzidata has a fascinating post on the core unexamined assumption of the left faith:  that everyone behaves as I do and therefore the coercive policy that I advocate will yield the behavior that I project in myself.

Another consequence of the unexamined assumption that everyone is like me is that society becomes quite easy to plan from the top, because we all have the same tastes, preferences, ambitions, beliefs, and ways of going about things, don't we? Us deciding about how to satisfy other people's wishes does no great harm, because we effortlessly know what these wishes are. They are just like ourselves.

Kind of odd coming from people who make such a fetish of 'diversity'. Of course their diversity is never one of thought or belief, only of gender, pigmentation and facial structure.