Just curious: Is there anyone around today who is considered a "shihan" who came up purely
in Aikido, with no other substantial martial arts background?
[Here, "shihan" and "substantial" are undefined, but I hope the reader gets the gist.]
When you come to aikido, you bring all
of your baggage with you. That means much
more than just any prior martial arts training; it's you as you are in your entirety
: physically, mentally, spiritually, and whatever else.
Once you do have the opportunity to bow in, you add a new dimension and maybe a new perspective to who you are. You'll have a chance to re-examine everything---especially any physical martial arts techniques / tactics / strategies you've picked up along the way---and decide what is worth keeping, what is worth changing, what adds depth, and so froth.
of this becomes your
Always beginner's mind. Then how can you go wrong?