The question becomes, “how does one adjust to the 21 foot, 1.5 second situation?”
Simple. Where possible, backup while drawing your weapon, thereby giving you more valuable time!
In such situations, it is incumbent on the attackee to be aware of their surroundings. In a possible other situation where it may work, turn and run until your weapon is drawn. Then defend!
When you are an older person, facing a physically fit young thug, moving away fast enough is unlikely to be an option.
But, once you draw, it is a good idea to put some distance between yourself and the attacker while commanding him to drop his weapon.