Pulled directly from the Youtube homepage....
The "Recommended for You" module picks videos based on your viewing history. Remember, you will get better, more specific, and more consistent recommendations by logging in.
And what did the system pull out for me? Monkey riding a bike to the tune of Oy Como Va by Carlos Santana. I <3 mass personalisation.
N.B I do not endorse the training methods that they might be using in this video...!