Hehe, that's going a tad too far, in fact thinking about walking down stairs can be bad for your health! I was walking down the stairs in my house a few years ago and partway down started thinking about how complicated walking up and down stairs really is, moving my knee this angle, hip that angle, shifting weight, moving my upper body, co-ordinating all those muscles at just the right time and keeping balance. Suddenly I froze as I wasn't sure what to do next, bent both knees at the same time, started falling and had to grab the bannister and stumbled down a few stairs.. Sometimes it's best not to think too hard ;-)
Ah yes, the notoriously flexible "common sense"!