爱 (traditional 愛) once held 心 (heart) at its center — to love was to offer your HEART, cradled by hands above and a slow step below. When the character was simplified, the heart was removed and 友 (friend) put in its place. Many Chinese gently lament it: 简体的爱没有心 — 'simplified love has no heart.'
爱 is the warmest character you'll learn. 我爱你 — 'I love you' — uses 我 and 你 from your very first lessons, now joined by love. 爱 also means 'to like to': 我爱吃 ('I love to eat'). 爱情 is romantic love; 爱心 is loving-kindness. It's a word the language treats with great tenderness.
Hands cradling a friend (友) — though the old form cradled a 心 (heart). To LOVE.
你 (you) was your first character. 我 (I) came soon after. Now, with 爱, you can write the most important sentence of all: 我爱你 — 'I love you.' You've been building toward it since day one.