True Robert, and as an aside there are always the "got my black belt and now I'm out" people...which baffles me. You'd think they'd be more pumped about learning after shodan shinsa, but I guess they figure they have the whole aikido think on lock.
I don't think it's that, so much. I get the feeling that more commonly, it's like that jolt when you come to the bottom of a flight of stairs and you were expecting a few more steps: you've been so focused on this task that you haven't been looking around you, just trudging along with your eyes on your feet...and suddenly, wham, you're "there". You look around, and for the first time you think, "Uhhhh...now what?" And then you find out now what: more training doing exactly the same things you were doing before you got shodan, only without the excitement and motivation of an impending test. Or maybe you have been thinking about what it would be like once you had shodan, and you find out that the reality is nothing like that. Or maybe you really shortchanged the rest of your life or neglected an injury or whatever to push through the test, and now those chickens are coming home to roost. It's all common enough in people who have worked long and hard for a goal, but who have developed tunnel vision along the way. Emerging from the tunnel can be a rude shock.