Pain and life
One thing I love about aikido is how strikingly it describes how your body works and how that is, in fact, how life also works.
In aikido, intertia signifies blockage of your chi energy. When there's inertia, you won't feel pain but, suddenly your arm could break or your neck could snap *gulp*. Aikido tries to unravel these blockages so that the chi would flow smoothly, as a result... you feel pain, tremendous pain sometimes. But that's a good sign. The sign of something in you actually flows correctly.
How life is very much similar to that. Sometimes, we don't feel pain... and suddenly, things start breaking, start snapping left and right. This is due to inertia within us, we "refuse" to see the pain.
There are times when pain is grabbing us by the throat. We can bearly breath just thinking how painful things are. Unbearable, unsurmountable... but be sure, the pain is merely there to show how things are actually flowing correctly.... If you ever feel such pain, be patient. It will soon be your turn to be a nage* :)
*In aikido, nage is the person who is doing a technique, as oppose to uke who is receiving the technique (the pain?)