I've got the same confusion - the friends I know who are familiar with MBTI put me quite easily in the category of introvert, and they are introverts themselves. My family does the same, even though they're not really familiar with the theory, and I assume remember quite vividly my teenage years, when I was very daydreamy and off with the fairies!
When I asked my INTP friend about it, she did admit that "I didn't seem to get tired of people", and she didn't know I interacted with other friends, so she couldn't really say.
But yeah, it definitely doesn't help with the whole categorisation thing.
Xander, I don't think all ENFPs love people, per se, but I think to a certain extent we can't help but be fascinated and drawn to them. It definitely depends on the people around you, and I certainly can't speak for every ENFP (especially since I'm not entirely sure I'm completely one myself! ) but I would think that an ENFP shunning all human contact is not a natural reaction, and possibly due to mentioned past event?