You want to know what's a terrible investment? Cash. It has lost more than 90% of it's value in the last 100 years.
Try living in a developing country. It loses 50% of its value in 15 years. By the time you save up for college, you need twice as much.
"On the Continuous Devaluation of the Roman Currency"
http://www.rmki.kfki.hu/~lukacs/ROMLAS.htm
http://www.rmki.kfki.hu/~lukacs/ROMLAS_files/image008.gif
"For in every country of the world, I believe, the avarice and injustice of princes and sovereign states, abusing the confidence of their subjects, have by degrees diminished the real quantity of metal, which had been originally contained in their coins."
https://en.wikisource.org/wiki/The_Wealth_of_Nations/Book_I/...