I was a fairly serious baseball player as a kid, and later got into golf, and what you describe is pervasive in those activities too. Coaches for generations have repeated things like "keep your elbow up" or "push off the rubber" that (accomplished) players don't actually do, and it's quite apparent if you watch any slow-motion video.

I also struggled with swimming until I was in college and realized that floating is more about filling my lungs with air than anything people told me to do with my arms and legs. My epiphany was that people could float on their backs without moving their arms and legs at all. Now my kids are in a great swimming lesson program, and they start everything with taking a big breath and puffing out their cheeks. I wish someone had just told me that as a kid.