Re: When did you stop being a beginner in Aikido?
In something such as Aikido, I'm very much of the opinion that you should always consider yourself a beginner to keep an open mind towards learning, so that you actually can continue learning, modestly and completely.
However, on face-value I think there's a lot to this question too; for me, I stopped feeling like a beginner after my first lesson after a ten year break from Aikido. Suddenly, all of these things that I didn't understand as a youngster became clear, and I thought, "yes, I get this". But I'll always be a learner with inexperiences to overcome and to learn, and I'll forever have further to travel on the Aikido path, probably never seeing the horizon.
If I humble myself too much with the 'always a beginner' mindset there's the risk I'll have too little confidence to truly learn and advance. It's all about keeping yourself genuinely modest.
But, of course, from a 'beginner in the grand scheme of things' point of view, Sandan does sound like a reasonable level.