I've been taking golf lessons recently, first time ever, and have found the lessons to be not only fun and interesting, but have applications off the golf course.
For example, I have a bad habit of "flipping" my left wrist after hitting the ball. They have worked with me on this, having me work on the separate steps of the golf swing, and breaking them down one by one. I even paid close attention to the TPC on TV to really analyze how they swing. And, practiced with my foam golf balls in my house while the TPC was on.
The point to muscle memory is this: if you have an improper way of doing something, such as a golf swing, and flipping your wrist, every single time you swing and flip your wrist, you are creating muscle memory. This means you will continue to do the action the same way until you are educated, and choose to break the habit.
Let's say you have the same routine every night. You go home from work, you change, you have dinner, spend time with the kids, watch tv, go to bed. Get up, repeat. For 7 days in a row. For 30 days in a row. For 365 days in a row.
This becomes your muscle memory. It's the habit and routine that we all crave, yet when we can't get ahead or change our lifestyles to attain our goals, it's this same habit and routine that will be our downfall - because that is what we are accustomed to.
I challenge every one to identify one area you want to improve. Notice your habits and routines, good and bad, that affect this one area, and strive to change them. You will be amazed how easy it seems once you've recognized what is holding you back. Good luck and share your accomplishments!