The IT Factor
No one can explain what the "it factor" is....
In the past the “it factor” might have been defined as someone with je ne sais quoi, or the indefinable something that makes someone special. The “it factor”, was also called the X Factor in some cases, and still may be referred to as such. Most often, it is applied to celebrities or semi-celebrities that seem to radiate charisma and charm.
I don't think IT is exclusive to celebrities though. People with IT are those you remember attended an event. They get left out of things intentionally, because they're completely polar... you either like them or you don't. No grey areas with people possessing IT.
People with IT get talked about. People with IT get dirty looks. The thing is, people with IT, are noticeable. Very very noticeable. Unforgettable.