鬼迷心窍 (guǐ mí xīn qiào) — to be obsessed (to the point of being irrational); to be possessed by a foolish fixation

A drawing of the thing itself, worn down over three thousand years into a few strokes.

鬼 originally drew a kneeling figure with an ugly face, perhaps a mask; the small lower right dot is a later added tail.

Most characters — around four in five — are built this way: one part hints at the meaning, the other at the pronunciation.

迷 uses 辵, the walking part, and 米, which gives the sound.

A drawing of the thing itself, worn down over three thousand years into a few strokes.

The shape of 心 comes from a drawing of a heart, now highly stylized.

Most characters — around four in five — are built this way: one part hints at the meaning, the other at the pronunciation.

This origin belongs to the traditional form 竅; 窍 is its simplified writing.

The traditional form 竅 combines 穴, meaning cave, with 敫 for the sound; the simplified 窍 is a shorthand.