B's

• several paradigms with functional, object-oriented thanks to python, smalltalk, clojure
• different languages
• show paradigms have different "units"
• new people :)

C's

• lost focus several times
• not lowering expectations of the domain

One-liners to do CountdownKata

• Python: range(10, -1, -1)
• Smalltalk: (10 to: 0 by: -1) asArray
• Ruby: (0..10).to_a.reverse
• Haskell: [10,9..0]
• Clojure: (apply vector (range 10 -1 -1))