思い込む

• Reading: おもいこむ
• Romaji: omoikomu
• Kanji breakdown: 思 (shi/omo) — think, feel; 込 (komu) — sink into, be included
• Pronunciation: /o.mo.i.ko.mɯ/

Meaning

To be firmly convinced of something; to be under a fixed impression; to have an unfounded belief.

A Group 1 (godan) compound verb from 思う (to think) and 込む (to go deeply into). Conjugates as 思い込ま-ない, 思い込み-ます. Often implies a belief held without sufficient evidence or in contradiction to the facts. The noun form 思い込み refers to a fixed idea or unfounded assumption.

Examples

1. 彼は自分が正しいと思い込んでいるので、他人の意見をまったく聞かない。 He's so firmly convinced that he's right that he won't listen to anyone else's opinion at all.
2. 薬を飲まなくても治ると思い込んでいたのは大きな間違いだった。 It was a huge mistake to be under the impression that he'd recover without taking any medicine.
3. 彼女への思い込みが人間関係を複雑にしていた。 Her unfounded assumptions were complicating her personal relationships.

Usage Guide

Context: psychology, daily life, relationships

Tone: neutral

Origin & History

Compound of 思う (omou, to think/feel) and 込む (komu, to sink deeply into). The combination conveys a thought embedding itself so deeply it becomes unshakeable conviction.

Cultural Context

Era: Modern

Generation: All ages

Social background: Universal