Numerology's core life path numbers run from 1 to 9, with 11, 22, and 33 kept unreduced as "master numbers" in most Western schools. 1 sits at the bottom of that range — the smallest single digit a reduction can land on, and the only one that can't be split into two different smaller digits.
That makes 1 oddly common as a talking point: because it's the first number, a lot of tradition has been built on the idea of "firstness" — starting, leading, standing alone before anyone else arrives. None of that follows from the arithmetic itself. The arithmetic just says: if your digits reduce to 1, your life path number is 1. What people do with that afterward is interpretation.