It's always bugged me, too, this thing where a person or a company takes pains to tell you what they think their virtues are:
- I'm a classy person.
- I'm an educated person.
- I'm a modest person.
- (Most any reference to "elegant" in a product description.)
Now John Scalzi has coined a term for this: McKean's inversion. He describes it this way:
The adjective a person says they are is frequently the thing they are not.
The name McKean's inversion originates via an indirect route. Erin McKean is a lexicographer (among her other talents) who once stated what's come to be known as McKean's Law: "Any correction of the speech or writing of others will contain at least one grammatical, spelling, or typographical error." Scalzi knows McKean and says he remembers how she once observed that ...
... if someone used the word to describe themselves, it was often quite obvious that they were in fact the opposite.
Thus the inversion. And as noted, McKean's Law was already taken.
It's a little early to tell, but my sense is that this is intended to be used for instances where the person is being a bit clueless. It would therefore not work when they're simply being disingenuous, e.g., "I'm just a humble technical writer." But who knows?