From my experience, the lion's share of learning to program is learning to read documentation - learning to find singular answers quickly, outside of narrative books and tutorials. It's something often marginalized on the way to absorbing the basic, shared, methodologies of programming but it requires both the resourcefulness to find good documentation and, once found, the patience to read it. And with practice comes the speed to dip into it without interrupting your workflow. Once a programmer has gained that literacy, the impact of forgetfulness and rustiness will be mitigated to the point of trivial inconvenience.