You trained twenty years agoSource 1
You remember what strong felt like, and you already know this is a different body. You do not need persuading that training is worth doing. What you need is a starting point that does not punish you for the twenty years in between, and a way back that does not begin with an injury in week five.
Amble starts below where your memory says you should be, deliberately. Muscle recovers coordination quickly, which is why week one feels encouraging. Tendon and connective tissue adapt on a much slower clock, which is why week five is where returning trainees get hurt. So the first block adds sessions before it adds weight, and adds weight before it adds intensity. Load rises when your own feedback says it can, following a graded progression rather than a calendar somebody else wrote.