How commonly do you guys encounter this? Students that have soloed but seem to have days where things just aren't coming together, for what ever reason, and a little pattern work becomes necessary before they are allowed to go out and solo again? What's the best way to handle this without being too discouraging, either for them or yourself and your own teaching abilities? Obviously more practice is needed, but why would someone suddenly seem to "forget" something they had been doing so well?