Personal advice means advice that is contingent on the advice-giver being right about part of the receiver's personality/worldview (if giver wrong, then the advice is rather worthless).

Or we can make it better, by realising that it's a continuum not boolean (boolean variables can only have two values: true or false).

The extent to which advice is personal, is the extent to which the value/truth of the advice is contingent on advice-giver being right about part of the receiver's personality/worldview.

Also there's a different continuum of note: how personal the advice is.

This depends on two things:

- the complexity of the relevant parts of advice-receivers personality. if giver only must get simple part right, it's not very personal.

- societal norms/taboos

The extent to which advice is personal, and how personal the advice is, usually go hand in hand (lots of one, lots of the other) but do not have to.