I am curling 20lb dumbells for sets of 50 and they told me to start doing non weighted arm curls this week with a goal of bands the following I was doing bands for sets of 100 a few weeks ago. I did not lose much strength. I have a lot of muscle memory. Regaining strength is a non-issue just working on overhead flexibility more. I even started to add back weight this last week
225lbs for the last 23 years, still 220 now without training
Looks like your muscle memory has dementia...