A lot of things we do, are done seemingly without thinking. Where is the line between muscle memory and normal memory/learning? And are there other things at play? A few examples: One of the doors in my house is a sliding door. I don't usually close it all the way with my hand, instead giving it a shove and it always slows to a soft tap as it hits the end. When driving, I look at the speed signs but not often at the speedo. It's like my foot knows where it should be for the given speed, slope etc. Walking and tossing something into a bin (a coordination of 2 velocities), when doing it without thinking, it always goes in. I'm sure you could think of others of the like, but one other thing has me curious. When the lights go out, muscle memory ain't so good. Try undressing for bed in the dark. Is it that muscle memory still requires visual information?