A preconceived notion or assumption held without sufficient evidence; a subjective impression or prejudice.
彼女は自分が正しいという思い込みを捨てるべきだ。
She should abandon the assumption that she is right.
思い込みで人を判断すると誤解が生じやすい。
If you judge someone based on assumptions, misunderstandings are likely to occur.
医師の思い込みが診断の遅れにつながったケースもある。
There have been cases where a doctor's assumption led to a delayed diagnosis.
それは単なる思い込みに過ぎない。
That's nothing but an assumption.