A knife 刀 separating the horn 角 from an ox 牛 — butchering, taking apart. From loosening joints to loosening knots to loosening confusion: untie, solve, explain.
解决 solve, 了解 understand, 解释 explain — modern life runs on 解. Zhuangzi's master butcher 庖丁解牛 carved oxen so perfectly his blade never dulled — the classic image of effortless skill.
KNIFE takes HORN off OX — take a problem APART to SOLVE it.
解 has three readings: jiě (untie), jiè (escort), and xiè — the last surviving mostly in the surname and 解数 'martial moves'.