Yes, it was just a sardonic comment, meant in jest, poking fun at myself. But perhaps it's indirectly helpful, here: others in the thread should note why you responded seriously. Without context, it isn't necessarily funny, and could conceivably be very serious in certain contexts, even with an emoticon attached. You don't get to see the wry look or the twinkle in the eye, or hear me chuckle upon reading your reply.
Humor has always been a funny thing.

Usually, when people accuse you of having no sense of humor, they mean that you didn't laugh at their joke, and, well, of course,
their jokes are always funny, right?
As for the INFP/INFJ thing, it doesn't bother me to let them have it out, so much as I keep on seeing the same patterns - hence the nail video. The video isn't meant to be insulting, it's meant to describe humanity in general. We're all almost willfully blind about certain things. (I am, too, though about different things that most.) It's a funny video because most adults have been on both sides of that archetypal interaction.
Personally, I believe the answer is to focus on becoming aware of one's own blind spots, and not put so much energy into pointing out those of others; that listening communicates better than telling.
And that's part of the intended humor of my original post in this thread: I realize that while
telling more might generate some interesting conversation, it's probably better that I sit back and listen and learn, for a while.