Arrrgghhhh. Nose wheel shimmy. On one of my first tngs, the nosewheel of the 172 I was flying went into a mad shimmy. I really badly wanted to shut the engine down and stop as, not knowing what was happening, I imagined the prop was about to come off.
However, I looked at my instructor, and he said keep going. On takeoff, the shimmy mercifully stopped. Phew.
I believe one of our students encountered bad shimmy on a first solo, and ran it off the runway as a result in panic. Scarey. Not sure if I quite believe this was the whole story, as could shimmy really make the plane that uncontrollable ??