There’s been plenty of explanations already, but here’s a perspective I think can help:

Your original intuition is entirely correct for an object that appeared next to earth but which isn’t moving relative to the sun. It would fall straight in with very little trouble. If it’s moving a little sideways then it’d need to be nudged to make sure it didn’t miss the sun.

But the Earth is moving super fast sideways, so an object coming from Earth would need to be nudged a lot to not kiss the sun.