An arrogant conceited supercilious condescending sociopath psychopath crackpot wackadoodle certainly is gonna assess his/her value at awesome big. Extremely. Profoundly. Wisdomly.
Similarly a modest person way well under assess his/her value because being a conceited a** is not his/her cuppa tea.
So who decides TRUE VALUE? Friends or foes are gonna skew it. What independent detached INTELLIGENT source is there to nail it?