As a licensed Whiggish philosopher, I can explain this consistency quite well: it stems from the fact that we experience the same world and share the same mental model of its causal structure.
Disagree that it's the complete same; there are differences between individuals in the level of development of that mental phenomena. Hence, in a sense, we each occupy a slightly different world, looked at through a slightly different lense, biased in a slightly different way.
