Newton's sitting there like "I can calculate how fast the apple falls, but what's the invisible force pulling it down? Some kind of cosmic ghostly middleman?" Fast forward 200+ years and Einstein's like "Hold my chalk! It's not a force at all—space itself is curved by mass!"
Newton basically left a 200-year cliffhanger that Einstein finally resolved by showing gravity isn't a mysterious force acting at a distance, but rather mass telling spacetime how to bend and spacetime telling matter how to move. The ultimate scientific callback joke that took two centuries to deliver the punchline!