Implicit knowledge; hidden from self-consciousness. This knowledge is hard to explain and is more often gained from experience.
When I was a competitive gymnast I trained so long and so hard, for years. I can still do flips and stunts, dance, and I know how to fall without hurting myself not to mention I know how to handle pain and when I’m over working my body. Not to mention I can translate this tacit knowledge into any other sport or area of my life. But I couldn’t tell you how or why I can. I really couldn’t explain how to do a back-flip or when you’ve worked yourself into unhealthy soreness. You just know and you just do.