"Each person who comes to the world comes for a personal and unique rectification, and no person resembles another [regarding each one's individual rectification--MR].
Each person has an individual path and way to rectify and trod, for which he has come to the world."
It's like you're walking around mostly whole, but you have a gap or a hole in you somewhere. (When people speak of "feeling empty" or "missing something" or having "a hole in their heart," this is likely what they mean without realizing it.)
Yet as long as a person resists filling and completing what he lacks, he's incomplete, says Rav Erez.
So what do people do instead of filling that very real "hole"?
They seek vitality and pleasure from the material world.
This is the real root of all addictions and bad habits.
As Rav Erez says:
"As a rule, a person cannot live in a vacuum (chesaron); he must have vitality and pleasure."
["Ki yesh klal, sheh ha'adam lo yechol l'chiyot b'chesaron; hu chayav chiyut v'taanug."]
Rav Erez notes that even if a man learns Torah and merits to come close to the Truth, and even if a person is okay from every aspect and truly strives to do the right thing, nonetheless Rebbe Nosson explains that even such a person still needs to merit finding his personal individual path in the world.
He goes on to say that this is the deeper meaning of the verse "Rachel weeps over her children...for they are not..." [Yirmeyahu/Jeremiah 31:14-16]:
"She weeps over the fact that not every person goes on his own individual way and path."
And yes, some of these voices are hints from Hashem as to your personal path in life.
But some are simply well-meaning people (or sometimes truly awful people) who are mistakenly projecting their rectification onto you (or simply trying to crush you), and trying to pull you off your path and onto theirs (either because their own path is working out so well for them and they feel it's the Ultimate Truth or because they can't appreciate yours).
However, it's very important and tremendously more gratifying to stick to your own path.
Most importantly, it's the way Hashem wants you to go.
The above translations are mine; therefore any errors are also mine.