Normal people define "true" as "good enough; not worth looking at too closely". Nerds define "true" as "irrefutable even by the highest-level nerd you are likely to encounter in this context." Hence more or less all of Western philosophy, theology, science, etc.; and hence normal people's acceptance that contradictory things can be "true" at the same time.

(Yes, I'm problematizing your contrast between various groups you dislike and "normal people".)