(always in the phrase "stickler for") perfectionist
You'll find that in my edit of your essay I've changed many of your periods to semicolons. I'm a stickler for punctuation.
Stickler is one who always has a stick in his hands. Such people are STRICT DISPLINARIANS. Read it as STICK-LER, i.e. one who sticks to a set of rules, a PERFECTIONIST.