As you mention in your post its more about keeping up with the moving bleeding edge rather than keeping what you have. The most important point/habit is to be invested in lifelong learning.

The moment you stop learning, only doing rote work, is when you stagnate. Thankfully I don't know almost anyone in software who can do even a days worth of work without something unexpected happening. As we all know, execution of a plan is never as simple as the plan. Each unexpected moment is an opportunity to learn, make sure to squeeze those moments for learning and knowledge as much as you (and your employer) will allow.

If your job doesn't present many opportunities for learning then the answer would be to look for another job or hobby-projects if you have the time and energy available.