Like a white colt flashing past a crack — time flies.
Tips
culture
驹 specifically denotes a horse under two years old (per 《说文》). It anchors the famous chengyu 白驹过隙 'a white colt darting past a crack' — Zhuangzi's metaphor for the brevity of human life.
memory
马 (horse) + 句 (phonetic) — a small horse that is just one sentence (句) long, not yet a full grown stallion.
Horse radical on the left fixes the subject: 驹 names a young horse — specifically a colt or foal. The radical groups 驹 with the rest of the horse family: 驴 donkey, 骑 ride, 骏 fine steed, 驰 gallop.
Right side supplies the sound: jù → jū (tone shift). 句 is a pure phonetic here with no semantic contribution. Same phonetic anchors 拘 detain, 局 office, 桔 tangerine — all sharing the jū/jú/jù reading cluster.
