I can weld anything, any position, overhead, in a trench, flat on my back. Thirty years of it. Now my shoulder won't lift right, there are spots in my vision from the arc, and my hands don't hold as steady as they did. The skill is all still there. The body it lives in is wearing out.
More people experience this than they realize.
You can weld anything, and your body and eyes are paying for years of the work.
If this sounds familiar, the Library can help you find the bigger picture.