No question about it muscle memory is real . When you lay off for whatever reason just like if you wear a cast the muscle will atrophy as the body has no interest in maintaining muscle it does not need . However as you develope the muscle seems to remember that last point and will rebuild that muscle alot faster than getting it originally . I had a 7 yr layoff after being diagnosed with cancer in 2003 . Went I returned to the gym it was just to lose some fat and maybe tone up a bit . To my complete amazement I grew faster and more than I ever dreamed , much faster than it took to get to that point originally . If you talk to other guys who've been at this for some time and I think most will agree there is something to this thinking .