Numerologists split the birth name into two piles: vowels and consonants. The vowels supposedly reveal the soul urge, your private wanting self. The consonants become the personality number — the self other people bump into first, before they know anything real about you.
Reduce the consonant total for a 3, and the tradition hands you a fairly consistent sketch: quick with words, comfortable being watched, allergic to silence in a room. It's the numerology equivalent of "the funny one" — a label that's flattering right up until it's the only thing people see.