I disagree. I've met very few NTs in my life, and even if I have met any, they've never been particularly recognisable.
At the risk of sounding arrogant, I'd say I was quite a rare breed based on the people I know. That isn't to say I'm the only unique one; it's just that a lot of them are clear SPs. I've met a few NFs in my life, and I much prefer their company to that of the SPs (who I can clearly see make the bulk up of my circles of friends). I met my first SJ outside my family (my grandad is an SJ, probably extraverted, and my grandma I think is also an SJ) on coming to uni, the September just gone.
Maybe it's because you associate yourself with more of your 'own kind', Belfry. For example, at school, college or uni, was your clique or group of friends made up of people who were inherently NTs (and maybe a few NFs)?