Many yearn to live spontaneously; it's not uncommon for INFJ actors to take on an SP (often ESTP) role.
Awareness of extraverted sensing is probably the source of the "SP wannabe" side of INFJs.
"There's something rotten in Denmark." Accurately suspicious about others' motives, INFJs are not easily led.
These are the people that you can rarely fool any of the time.
Beneath the quiet exterior, INFJs hold deep convictions about the weightier matters of life.
Those who are activists -- INFJs gravitate toward such a role -- are there for the cause, not for personal glory or political power.