I once walked into a supermarket and really started to look at what was available, every item, how I could buy fresh oranges in the middle of january, trying to imagine the insane number of persons who had to a involved in all the globe spanning supply lines.

It doesn't compare to brain surgery, but the experience was so profound it came close to breaking my mind (if such a thing is possible), I had to give up and leave, because I just couldn't take it.