My mind was blown by this simple video from Neil DeGrasse Tyson about the ocean's tides.
I thought that the tides were created when the Moon pulled the ocean toward one shore or another. But in fact the moon creates an oceanic bulge that the Earth is constantly rotating through. When the tide "comes in," the tide isn't coming toward you, you're rotating on the Earth into the tide!
Or maybe it's more accurate to say that you're rotating on the Earth into a position in relation to the moon where its gravitational pull causes deeper waters.
Here's a video that explains it all very well and thoroughly. I still don't have an intuitive understanding of why the moon's pull on the near side of the Earth creates a tidal bulge on both the near side and the far side, but I'll have to sit with that.
I'm going to have to call my kids and tell them I explained it to them all wrong that day on the beach.