So I'm not sure if this applies to all INFJs, but I'm sure most.
Depending on who I'm talking to, I can be a completely different person.
This goes much further than just being more crazy around friends and more respectable around grandparents.
To who I talk to, my voice can be very different, not just the tone, but my voice, the thoughts that go through my head can be extremely different, and so much more...
After being with some people, I think a few minutes later, "Was that really me?"
I completely change to a different person uncontrollably just talking to every day people.
Who can relate?