It is an alien world that is around us. Literally.
It's outside of our experience, if our own thoughts are the only measure of reality that we can have.
I watch a bee fly over the flowers on my patio. They're beautiful shades of pink and orange, and the bees have been busy lately, buzzing from bell to bell. I watch them and wonder what it would be like to be a bee. They get to fly and crawl around miles and miles of gorgeous flowers to gather the very energy that their society needs to sustain itself. They fly back and sometimes do a fancy dance for their identical siblings, informing the hive of the location of a particularly plentiful patch.
An alien kind of existence. Their communication system so different, so unintelligible to humans. We're going to have to spend millions in research grants, thousands of hours of effort, entire buildings built, and gigabytes of data across the globe will go towards understanding what one bee tells another by way of its dancing and buzzing. A task that their tiny minds are incredibly well-equipped to perform.
We are spending ourselves to understand the language, the grammar of bees. Because we wish to know their alien thoughts.
And of course our own thoughts are little-more understood.