which way was up
The whole paragraph is: " Sometimes I got my majors mixed up. A number of my fellow religious-studies students-muddled agnostics who didn't know which way was up, who were in the thrall of reason, that fool's gold for the bright-reminded me of the three-toed sloth; and three-toed sloth, such a beautiful example of the miracle of life, reminded me of God."
My question is:
1 what does "which way was up" mean? Does that means "which way was right"?
2 why did author say that reason was "fool's gold" for the bright?
Best wishes
Thanks very much!