What does it mean that a critical thinker distinguishes "truth" from "usefulness," and knows the limits of perception?

Our access to the world is always filtered and incomplete, so a belief can be useful (it helps us act) without being true — a critical thinker keeps the two apart instead of mistaking one for the other.

Human perception and interpretation are bounded: we never see the world raw, only through our senses, concepts and prior assumptions. From this Budelacci draws a warning about a subtle error — sliding from "this belief works for me" to "this belief is true." A model of the world can be practically convenient, comforting or socially rewarded and still be false. Critical thinking holds the question "is it true?" separate from "is it useful?" — because conflating them is how convenient illusions get mistaken for knowledge.