Aiki ken v.s. reality.
I just found a great example on youtube of the difference between concepts/theory and fighting.
http://www.youtube.com/watch?v=zEsMuvBwdDk
In the beginning you can tell it's just two Judoka going at it, with shinai. Basically you could say they are playing "whacky-sticks".
Then you start throwing Kendoka in to do jikeiko and we see something strange happen. The Kendoka clearly have better movment and skills with the shinai. However the pure violence of action, and power of the Judoka often win him the bout, or end in mutual strikes.
Fighting and training are different animals, until you've done both it's hard to understand this. As David Skaggs likes to say: "in theory, there is no difference between theory and practice. But, in practice, there is".