笑 puts bending 夭 under bamboo ⺮ — the classic explanation: bamboo swaying in wind looks like a person doubled over in laughter. Etymologists argue; everyone else just enjoys the image.
笑 lights up the language: 微笑 (smile), 开玩笑 (to joke — 别开玩笑! no kidding!), 笑话 (a joke — and 闹笑话, to embarrass yourself), 可笑 (laughable). Texting made 哈哈哈 and the ambiguous 呵呵 (a cold laugh — beware) into tone-of-voice art. The proverb keeps it warm: 笑一笑，十年少 — one laugh makes you ten years younger.
Bamboo ⺮ doubled over in the wind — LAUGHING.
呵呵 in a Chinese text is NOT a warm laugh — it reads as icy dismissal. Use 哈哈哈 (minimum three 哈) to be safe.