I am wondering how, say a microsurgeon, keeps their hands so exceedingly still! Do they train you certain techniques as to how to keep them calm and not shaking, or does it come from pactice after practice? I try to keep my hands still just using a pen, and I can do it but there are small jitters. How does a microsurgeon keep them so still that they can direct a needle the size of a human hair through blood vessels under a microscope? Thanks for all the help!