I agree with your first point. I think that we can forget just what skill is involved in crafts and trades, including our own. Have you ever tried to build a brick wall? It's really hard! To do it well anyway. But getting back to nails - the skill and experience involved in wacking in nail after nail, in just the right place involves much more physical dexterity than I will ever have. It amazes me! As do chefs and their hypersonic chopping skills!