• In Knot theory class, when we were supposed to “attach a cylinder to a surface”, I blurted out we need to attach a wormhole.
  • In ODEs class, I once said “you can extend every continuous function on the closure of its domain”. This is obviously false as the necessary condition on metric spaces is that the function be uniformly continuous.
  • In topology class, I once started describing construction of while we actually needed the construction of