Skilly, very good points.
Also, I find that when I cast a lot my body and mind start to calm down after the intial excitement and arenalin surge from going fishing. Then I get into a groove where I start to save energy and cast smoothly and effortlessly. The rest of the week is much less on my body once I get over that 'hump'.
I hope when I am older I will start that way from the first cast. That's one reason I am a dedicated student of the cast today, to understand it so when my body is less durable I will be that much more economical with my casting energy