While Sensei would never begrudge anyone entry, the clogs serve as a subtle ‘Do Not Disturb’ sign suggesting that you might be better returning later.
Sometimes this can be a tricky affair. Some days I caught myself making up to 5 or 6 trips and been left wondering if Sensei’s not wondering around somewhere barefoot.
A friend of mine once told me that he arrived one day and saw that the window was open a crack so he decided to stay and watch Sensei train - in hope he might observe some secret techniques…
Ok, so maybe I was a little misleading with the title, but there you have it. Might not have been the secret technique you were hoping for, but sometimes Sensei’s best secrets are the most obvious.