'You don't know what you've got until it's gone' isn't quite right. If it leaves slowly enough, you won't notice it leaving and you'll forget you had it in the first place.
When you see it again, you reconnect with things that you didn't realize were missing it can bring back powerful feelings you didn't know you had.
When this happens, it is usually an individual experience, not easily shared. James Cameron's movie Avatar provides a rare exception. The lush, rainforest moon in the movie feels alive and provides a stark contrast to our climate controlled daily experience. It makes us realize what we're missing.
The Na'vi understand that the wealth of their world is in the intact ecosystems all around them, not in the room temperature superconductor 'unobtainium' that the humans are there to raid.
As you might expect, the native culture is very different than our own. There are moviegoers who are genuinely disappointed that they can't go live on Pandora.
Avatar provides a common point of reference for people who have become disconnected from our natural world. If your food comes from the store, there's a pretty good chance you're disconnected from nature, and can find something desirable about the connection between the Pandoran natives and their world.
Our innate desire for a connection with nature has been termed Biophilia by naturalist E.O. Wilson in his 1984 book of the same name. We evolved in harmony with nature, and we do better when we keep some in our lives.
That's one of the reasons we keep houseplants. Another way we keep in touch with nature is to binge on nature with trips to places like Costa Rica or the Amazon.
Another way to reconnect is simply to regularly spend time outside, in whatever way feels right to you. Whether that's a walk around the block, a weekly hike, skiing in the mountains, or something more extreme.
We have lost our connection with nature. We only realize what we've lost when we see, in glorious 3D, how good it could be. And then we want it back.
By all means see Avatar, but then take those same eyes for nature on a hike afterwards. You'll be surprised by what you see.
P.S. If you still don't want to go outside, the BBC series Planet Earth is a good second choice. You can order it online without leaving the house.