I suspect it is fleeting but occurs in most serious relationships at some point(s). The type of love changes in character over time. Eros agape etc.💜✌️
Discussion
Extended passion seems to be an artefact of extended adolescence; the same quality that creates artistic brilliance.
That's probably why I have it: I've never really grown up. I'm stuck forever in fairyland, admiring my gallant knights off to slay dragons, and hoping for a brighter future.
Incorrigible optimism.