Agreed 100%...some of us go into surgery in great shape and come out flying...others go in a depleted, exhausted mess and take much longer to come back from it. Age is more of a factor, sooner, for women due to menopause and the side effects that it can cause like thinning, weakening muscles mass etc.
For men, testosterone helps you keep up your muscle mass longer and allows for somewhat faster healing compared to us girls (sorry girls, biology will always out)...so, if you are in good shape, no underlying diseases, careful of your nutrition (within the scope of your possibility) and have been active, although it is never a walk in the park, you should come through just fine.
I always do better when I am physically healthy before going in...
So, prepare, build yourself up and do your best...the rest is up to your surgeons and your biology.