...it only happens with girls I connect with. Like they have to enjoy sex, and she has to have lots of reaction during sex for me to to be able to be in that "moment" that you described. Basically I have to click with that girl...
there are people who have written about this in a serious vein: the concept of the extended orgasm. i guess if u go back to the Kama Sutra, humans have always been interested in elevating sex to a higher plane than that of mere procreation. but the EO people are serious when they describe orgasms lasting 30 minutes.
who knows what's going on? personally, i've only noticed two things:
1) what AsnDragon said above. partners are critical: some gals like sex and aren't that goal-oriented, some are definitely looking to finish, and some wanna roll off one after the other. i once had a (platonic) friend who was advising my girlfriend at the time about orgasms, with me sitting there (she wasn't shy). she said: "ya know when you shift gears on a motorcycle? it's like that: the first one revs up quickly, then you drop a gear and rev up more slowly to the next one, then drop another gear..." always loved that analogy. but everyone's different.
2) this isn't a sport for younger men. in my 20s, i just wanted to get off--as many times as possible. u get older and u start paying more attention.
i think attention and concentration are part of this elevated-sex deal. another thing: setting aside time for extended sexual interludes is at odds with our increasingly facile digital culture, where people check their Facebook accounts every five fucking minutes. u gotta have patience, a shared understanding with yr partner, and you must be In The Zone, whatever that is and however u get there.
there a lot of mystery, but that's sex! we humans explore, we're not simply fertilizing eggs and making a thousand offspring, like fish or amphibians, knowing most will be predator-snacks but enough will survive and keep the species going.
JtB