你 is a later arrival than the pictographs around it: writers took the person radical 亻 (a slimmer 人 you already know) and set it beside 尔, a word that had meant "you" on its own since classical times. Nail a person onto an old pronoun and you get a clearer, more everyday way to say "you" — a character built from meaning plus sound, not drawn from life.
A piece of culture
The polite 您 你 has a more formal cousin: 您 (nín), built by placing a heart 心 underneath it — respect, quite literally, rising from the heart. Waiters, students addressing a teacher, and strangers on the street reach for 您; family and close friends keep things simple with plain 你. Cantonese never adopted 您 at all, so 你 alone covers every situation there — one small way the two languages grew apart from the same root.
Use it in a real word
你我
nǐwǒ · nei5 ngo5
you and me — a natural pairing once you hold both pronouns, as in "你我之间" ("between you and me"); you already know 我