[matusp]

Simple illustration of what you are explaining in 1D. Imagine a simplified Earth:

Water -- Ground -- Water

Now let's add a Moon with gravitational pull. The pull stretches the system, because gravity is stronger the closer you are to the Moon.

Water ---- Ground ---- Water -//- Moon

The water is farther away from the ground on both sides now, since both sides stretched.

[heavenlyblue]

so why is left water further away from ground? this example make 0 sense

[nicwolff]

The Earth is being pulled away from that water, just as the water on the right is being pulled away from the Earth.

[adammarples]

But the water on the left is being pulled by everything to the right of it, moon, earth, other water. Why is it left behind? Every single thing is being attracted by the same centre of gravity on the right of the earth

[lostmsu]

It's further away so it's pulled less, so it shifts less.