Some mistakes begin with saying yes because saying no felt uncomfortable.

A great many bad outcomes begin with an agreement made to avoid a moment of awkwardness. The discomfort of refusing feels immediate and large, and the cost of agreeing feels distant and vague, so the trade keeps looking reasonable right up until it is not.

Practice a plain refusal this week on something low stakes. No elaborate reason. The awkwardness lasts a few seconds, and the ability to produce it is worth an enormous amount over a life.