The late Don Downie back in the day was a noted Southern California pilot and CFI living in Glendora in the Sierra Madre Mountains foothills northeast of the Los Angeles basin. In the mid 1960s and beyond he was a Contributing Editor to AOPA Pilot magazine with a monthly column on primary flight training. I read his writings religiously as I was learning to fly in 1965-'66. (Membership in the Aircraft Owners and Pilots Association (AOPA) was predicated on having soloed an aircraft back then).
Don had a pristine Cessna 170B taildragger and taught his daughter Dana Downie to fly. One evening he flew this aircraft to Point Mugu NTD where I worked to speak with the Point Mugu Aero Club on his flying exploits, having prior permission granted to land at the US Naval military installation. He returned to his home airfield the same evening, although late as he was such a great aviation topic speaker asset.
Downie had one absolute "quirk" mandatory prerequisite for teaching any prospective student pilot going for the Private ASEL rating certificate. Name this "quirk" of Don's that served him in good stead, turning out outstandingly well-trained proficient pilots.