So as an INFP, I *cough* sometimes *cough* see something there when it's not there but I can't see that it's not there because I'm so wrapped up in my fantasies and etc, then how do one know if it's actually there?
I don't know if delusional thinking is an INFp trait but it is often included in the profiles of the insane and serial killers. If it turns out to be the latter, then congratulations. You're well on your way to becoming famous.
No, it's just something that happens when the Introverted functions are allowed complete autonomy without influence from the outside.
In other words, flex your Extraverted functions