I think this is true for most people, but I have heard of some people (in rare circumstances) being solitary and largely asexual (having little to no care/desire for sex or intimacy).
That would be me. I'm a 53-year-old male virgin, and asexual; I've just never been interested in having sex with anyone. And I've found that while I've liked dating someone once or twice a week, a more full-time relationship is too much for me.