You should have spent last week getting your list of symbols straight and locked in your mind. Now you get to apply this to another week reading code on the internet. This exercise will be daunting at first. I'm going to throw you in the deep end for a few days and have you just try your best to read and understand some source code from real projects. The goal isn't to get you to understand code, but to teach you the following three skills:
When you do this exercise, think of yourself as an anthropologist, trucking through a new land with just barely enough of the local language to get around and survive. Except, of course, that you will actually get out alive because the internet isn't a jungle. Anyway.
Here's what you do:
That's it. Your job is to use what you know so far and see if you can read the code and get a grasp of what it does. Try skimming the code first, and then read it in detail. Maybe also try taking very difficult parts and reading each symbol you know outloud.
Now try several other sites:
On each of these sites you may find weird files ending in .c so stick to .rb files like the ones you have written in this book.
A final fun thing to do is use the above four sources of Ruby code and type in topics you are interested in instead of "ruby". Search for "journalism", "cooking", "physics", or anything you are curious about. Chances are there's some code out there you could use right away.