This reminds of something I read when I was quite young (maybe 10).
There is a block of granite, one mile long, one mile wide, and one mile high.
Every 1000 years, a small bird returns and rubs his beak on the block.
When the entire block is worn away, one day of eternity has passed.
It was a mind-expanding (and chilling) experience.
I tried to grasp the concept of "forever"
. . and later the concept of "infinity".
(I'm still working on it.)