Riding From Hunger

 When you reach a certain age, you see young people who don't ride nearly as much or eat as well as you do, but are skinnier.

Here is one possible explanation:

This came from a New Yorker series, "Cyclist Hand Signals and Their Meanings," by David Ferrier.

I have to admit that I never worked an unpaid internship.  But I have worked for very little money and, like the cyclist in the illustration, survived on food not bought in my local bodega!