Marriage has changed dramatically over the centuries. The resolute defence of "traditional marriage" by the trogs is really just defending the status quo -- which is vastly different from the way things have been over several millennia.
None of the emotions that we expect to find inside a good modern marriage are unusual in themselves. We find them well described in art and literature across all cultures and eras. What makes modern marriage extraordinary in its ambitions is the expectation that these emotions should reliably be entertained over a lifetime with the very same person.
The Troubadours of 12th Century Provence had a complex appreciation of romantic love: the aching generated by the sight of a graceful figure, the sleeplessness at the prospect of a meeting, the power of a few words or glances to determine one's state of mind. But these courtiers expressed no wish to combine their prized emotions with parallel intentions to raise a family, or even so much as to sleep with those they ardently loved.
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