I think what you're seeing here is that when you initially build muscle, you are building new muscle cells. When you lose those gains, you still mostly have the same number of cells, but they muscle fibers in them reduce. When you go to regain it, it's easier to regain because you still have most of the celluar framework there.
Or, at least, that's how it was explained to me. I probably have some details wrong.
I don't know if muscle memory is a scientific term but I understand it as adaptations of muscle and nerves that are skill specific as a result of training. I think it's hard to put a boundary around the brain here. The brain and the nervous system is also a component of strength.
aqueueaqueue probably meant this part ^. If you do steroid once, then you stop doing steroid, its effects remain, according to wiki (in mice).
Or walking. Humans take such a long time to gain the muscle strength and the motor skills to simply take a few steps.
Could you elaborate your training regime?
If you can do 3 reps of bench with 100kg-s, you do:
1. bar x 10, 2. 40 x 10 3. 60 x 5 4. 80 x 5 5. Then do 100 x 3
And then you move to squats and deadlifts with the same approach.
Is this more or less what you did?
I'm not sure if I would start deadlifting with my 3 max without proper warmup. Or any heavy lift for that matter.
What was your 3 rep max for the big lifts?
But the relevant bit is 5 years after that, I tried 1/4 the dosage, plus only 15 minutes in the gym every day (1 set of 3-rep max of each of the major lifts). I got just as big, and was actually stronger than I had ever been thru the full dose cycles.
Outside of the gym, I regularly halve the dose of any prescriptions or suggested dose of recreational drugs. A friend even told me he saw a Buddhist monk take a tiny shot of liquor and sit and meditate on that single shot for hours.
And finally, if I may take a sad turn, my father got trigeminal neuralgia but he's largely avoided all drugs all his life, so the standard dose hits him way too hard.