Characters
You don’t always have to be who they want you to be, you know.
— Kat ‧ 10 Things I Hate About You

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
The speaker offers gentle encouragement to stop performing for others' approval. Being who someone else wants is not compulsory, and the closing "you know" makes it sound like a reassuring reminder of a freedom the listener already has.
Context reviewed