Social Creatures and Ideology

Famous recluses kept journals about their day-to-day activities, and their philosophical observations. Even in the cases where men fled the city to be with nature, they kept writing to stay in contact with some element of humanity, or just to have an imaginary friend. (As an aside, are there any famous nature women who went off to live in the wilderness?)

People seem to be very attuned to the social context of what they think and say, and ideologies seem to be really wound up with human relationships, rather than stand-alone, divinely ordained doctrines. The 2016 presidential election in the United States demonstrated how the political parties in the US aren't really ideological, but are vast patronage networks.

This also explains cult behavior. Belonging to a group is possibly the most powerful human motive. Otherwise rational people will decide to believe some rando dude's a messiah.