My signature isn't even my name.
Nobody cares, and nobody looks at it. You could draw some flowers and nobody would give a ****.
Your dad is the one who doesn't see how the world works. Thinking that your signature actually matters in any particular way whatsoever, now THAT'S narcissism. Your signature is even less significant than your life.
EDIT: Also, if anything, your signature should be illegible as to prevent forgery.