September 11, 1933:

"anyone who looked for a source of power in the transformation of the atoms was talking moonshine."
- Ernest Rutherford

The very next day, on September 12, 1933:

"As the light changed to green and I crossed the street, it ... suddenly occurred to me that if we could find an element which is split by neutrons and which would emit two neutrons when it absorbs one neutron, such an element, if assembled in sufficiently large mass, could sustain a nuclear chain reaction.

"I didn’t see at the moment just how one would go about finding such an element, or what experiments would be needed, but the idea never left me. In certain circumstances it might be possible to set up a nuclear chain reaction, liberate energy on an industrial scale, and construct atomic bombs."
- Leo Szilard

Nuclear energy went from impossible to possible in less than 24 hours. World-changing breakthroughs can happen overnight. Though it hasn't quite happened yet, we may be in for similar shocks in AI.