How big is a googol (10^100)? Or a googolplex 10^(googol)?
The best answer I have found so far goes as follows. It the entire observable universe were divided into a grid with the size of each unit of that grid being one cubic micrometer (about the size of a fine dust particle). There would be about one googol of grid units.
A googolplex would be the number you write out in each of those grid units.
Next thought what is the largest number I can currently visualize? Well that would be the size of the observable universe divided into plank volumes times the amount of time it would take for a super massive black hole to decay. Where each grid unit has it's own unique grid time for the entire life of the universe(ish).
This is the largest number I can currently imagine and is still a crazy number of orders of orders of magnitudes smaller.