Touch typing you usually end up basically 'sending the commands' to your fingers before you put much though into it. So if you are off by 1 char or forget which mode you are in you can really destroy yourself. Most touch typing is also taught without you even looking at the paper/screen. The idea is your imagine what you want expressed and your fingers just 'do it'. I have done both of those things hundreds of times. I will do them again. As typing is just something I do not put much thought into until something is very wrong. At 90WPM you can get a lot of chars in before you figure out you have reallllly messed up.