Act, Don't think. This is like firing a tracer bullet. In code write something quickly which is cheap and brittle. If it does the job then expand on it, otherwise fire another tracer bullet. I must confess that my analogy makes me queasy, human life and all that.

Train as you fight. I think this can be applied quite simply. For perl it could be written as 'obfu when your off-work'. For me getting to grips with map relied heavily on obfu-like challenges that would not crop up in normal coding. Now that I can use map I can see all the times when it can be used where before I would have used a foreach loop or similar.

Update: Train as you fight is (I think) meant to be 'Train in the same way you fight', not 'Train whilst you fight'. Bizarrely I seem to have missed both possible meanings with my comment above. Hmm, normal service will resume shortly...