Things that call my attention

Car versus Man.

The car can only use gas to run, if you put something else in it, it won't work.
On the other hand the man is a extraordinarie machine. It can extract energy from thousands of sources.
I heard that people stranded on an island survived the 3 or 4 weeks prior to their rescue solely by eating the coconut flesh and drinking its water.
A neighbor of my mom in her home town managed to live almost 100 years, and his diet was mostly composed of the most basic foods, like corn tortillas and beans.
It can also create energy from sodas, chips, fried food, and almost anything that you throw at it. Of course, with no so pleasant secondary effects.