What I find interesting, and somewhat disheartening, is that the people who are incompetent and constantly brag about themselves, actually tend to be more successful because people admire confidence.
I actually think that in many cases it is more difficult for someone who is knowledgeable to convey that sense of certainty because in so many technical situations the technical answer to simple questions is "it depends on the details of what you want to do". The "right" answer in a sales context is usually "yes, this will solve your problems" and worry about the reality once the contract is signed.
I have always felt that Richard Feynmann's greatness devolved largely from the fact that he was better at identifying things that he didn't know than his colleagues. Where one person might develop a theory that works to explain a particular phenomenon, Feynmann would understand that this answer would just reveal new questions, so he would dig further than others.
A little Learning is a dang'rous Thing;
Drink deep, or taste not the Pierian Spring:
There shallow Draughts intoxicate the Brain,
And drinking largely sobers us again.
Fir'd at first Sight with what the Muse imparts,
In fearless Youth we tempt the Heights of Arts,
While from the bounded Level of our Mind,
Short Views we take, nor see the lengths behind,
But more advanc'd, behold with strange Surprize
New, distant Scenes of endless Science rise!
So pleas'd at first, the towring Alps we try,
Mount o'er the Vales, and seem to tread the Sky;
Th' Eternal Snows appear already past,
And the first Clouds and Mountains seem the last:
But those attain'd, we tremble to survey
The growing Labours of the lengthen'd Way,
Th' increasing Prospect tires our wandering Eyes,
Hills peep o'er Hills, and Alps on Alps arise!
"A little learning is not a dangerous thing to one who does not mistake it for a great deal." -- William A White
option 2 is by far the easiest and thus the most chosen one.