My personal feelings and views about anal sex are from a gay perspective.
i discovered my anus as a sex organ way before my penis, i think i was about 7 or 8. i was at a friends house and he showed me an enema kit and nozzle and gleefully explained how it was done. i secretly had a crush on Him and as soon as i got home, i found our enema in a cabinet in the bathroom and the nozzle became my first dildo.
For me, anal penetration has always been associated with another person, or fantasy about a penetrating person. In retrospect, i've been able to piece together and see my earliest 'sub nature' and how i was attracted to 'Dom' guys. The first time i penetrated myself with that enema nozzle, i connected the act with the boy who told me about it.
i ascribe to the spectrum theory of sex, it makes sense to me and seems to fit. i see identifiers like Top, Dom, on one end, versatile somewhere in the middle and bottom, sub, on the other end. i know that's a personal point of view, that there's such a thing as sub tops, though that doesn't really fit for me. Though most of my sexual experience is with guys, i think women can be "Top, bottom or versatile." One of the reasons i think my marriage to a woman was so difficult (besides my being gay lol) was because we were both "bottoms" and both pretty "sub." i also like the yin/Yang explanation sexually applied.
Besides the obvious physical pleasure i derive from anal sex, there are deep emotional/psychological components as well. i've come to view people as penetrators by 'nature' or receivers, or a mixture of both. i see some with a drive to create, to "penetrate" another with their person and leave a part of their person, or mark, on that person. The two seem connected to me. On the other hand, i see others with a drive to be penetrated by another, to receive a part of that person into their self and be 'marked' by that person.
Beyond the physical, anal sex for me is about receiving the need of the guy i am with to penetrate and put and leave a part of Himself inside of me. For me, when He orgasms, it's like His orgasm (and all that comes with it) is now mine... like He has put it, a part of Himself, inside of me and a part of Himself (way over simply put) is now inside and a part of me.
i have very detailed ideas of the Top/bottom, D/s, yin/Yang dynamic. i see anal sex as a physical expression of our emotional, psychological selves.