Oh boy, if only they knew what was coming! Right before quantum mechanics and relativity turned physics upside down, some physicists thought they had nearly solved everything. Then Einstein and friends showed up and were like "hold my theoretical beer" and BOOM – dark matter, quantum entanglement, and a universe that gets weirder by the discovery! It's like claiming you've finished a puzzle when someone dumps out another box with 10,000 more pieces. The universe is still laughing at our adorable confidence!