I still fall into a rabbit hole every-time i imagine infinity. it started when i was 5 or so. brain goes into a loop and imagines the infinite. for me it was and is connected to space. you have to hit a wall at some point, but then there is something behind the wall.. there can never be something that isn't there. the limited donut universe theory framed the space imagination. but the donut has to be surrounded by something. here goes the infinite loop again.

I think I know what you mean. When I was a kid, I got a feeling of complete emptiness lasting maybe couple of seconds when I was thinking about what if there wouldn't be anything.