This was a talk that I gave at SCNA 2011. It's a bit old but recently requested.

2. Mastery

3. Local Maximas

4. Focus

5. Masters can melt
people with their minds

6. We spend most
of our time here

7. Mihaly Csikszentmihalyi
on flow

8. What is flow?

9. I’ll give you a hint...

10. ?

11. Flow != meditation

12. The mental states are
remarkably similar

13. The flow of a master is
much more effective

14. Our nervous system
can only process 110
bits of information per
second

15. Effects
• Completely involved (no notion of self)
• A sense of ecstasy
• Inner Clarity
• Confidence in skills to solve the problem
• Serenity
• Timelessness
• Intrinsic motivation

16. Focus has an enemy

18. 25

19. When you over
caffeinate, your nervous
system can’t funciton
properly

20. You can’t enter proper
flow when in this state

21. BS!

22. We spend most
of our time here

23. Achieving mastery
requires proper focus

24. How do we get there?

25. Power

26. Power comes in
multiple forms

28. Locality

29. Know when to apply
what kind of power

30. Sometimes
power > elegance

31. Work in tools that
allow flexible
application of power
and elgance

32. Simplicity

33. example:
refactor apache
commons isBlank
33

34. initial implementation
public class StringUtils { !
public static boolean isBlank(String str) { !
int strLen; !
if (str == null || (strLen = str.length()) == 0) { !
return true; !
} !
for (int i = 0; i strLen; i++) { !
if ((Character.isWhitespace(str.charAt(i)) == false)) { !
return false; !
}!
}!
return true;!
}!
}
34

35. - type decls
public class StringUtils { !
public isBlank(str) { !
if (str == null || (strLen = str.length()) == 0) { !
return true; !
} !
for (i = 0; i strLen; i++) { !
if ((Character.isWhitespace(str.charAt(i)) == false)) { !
return false; !
}!
}!
return true;!
}!
}
35

36. - class
public isBlank(str) { !
if (str == null || (strLen = str.length()) == 0) { !
return true; !
} !
for (i = 0; i strLen; i++) { !
if ((Character.isWhitespace(str.charAt(i)) == false)) { !
return false; !
}!
}!
return true;!
}
36

37. + higher-order function
public isBlank(str) { !
if (str == null || (strLen = str.length()) == 0) { !
return true; !
} !
every (ch in str) { !
Character.isWhitespace(ch);!
}!
return true;!
}!
37

38. - corner cases
public isBlank(str) { !
every (ch in str) { !
Character.isWhitespace(ch);!
}!
}
38

39. lispify
(defn blank? [s] !
(every? #(Character/isWhitespace %) s))
39

40. initial implementation
Mutable state
Condition
public class StringUtils { !
public static boolean isBlank(String str) { !
int strLen; !
if (str == null || (strLen = str.length()) == 0) { !
return true; !
} !
for (int i = 0; i strLen; i++) { !
if ((Character.isWhitespace(str.charAt(i)) == false)) { !
return false; !
}!
}!
return true;!
}!
}
Exit point
Loop
Exit point
Exit point
40
Condition

41. Ok, i’m confused, how
does this apply to
mastery?

42. Focus and flow let us
realize our potential

43. We learn by stretching
beyond our limits

44. Entering flow helps us
become more self
aware

45. And sometimes here
We should be tactically
moving here

46. Effective focus helps
you level up faster

47. You need to work with
tools and languages that
allow proper focus

48. Choose sleep over
caffiene

50. Thank You!
•
•
•
aaron@clojure.com
@abedra
thinkrelevance.com