More than 60 years later, the phenomenon of the seven-year itch is now more of a catch-all for general disappointment in a long-term relationship and an urge to move on from it and try something else.
This week marks my seven-year anniversary with my husband, and it has led to a lot of thinking about what it means to be with somebody for this long.
Year one is often referred to as the honeymoon period. The time at which a couple can't keep their hands off each other; where everything is champagne and roses and every moment is absolute bliss.
I can't say from personal experience that's my truth, because I felt like the first year of marriage was full of questions and expectations from others, and being tired of smiling whenever somebody says, "Isn't being married the best?"
Seven years on, however, I haven't experienced a fervent irritation in my marriage. Neither of us have had an irresistible itch to scratch in terms of cheating, although we are realistic and trusting and appreciate that monogamish-ness is really the ideal.
So what is it about seven years with another person that lights this fire – the move from only being able to think about each other, to the want to touch (or be touched) by someone else?
For many couples, I think Monroe had it on-point. People need to feed wanted. They crave attention, and after seven years, it's terribly hard to keep your original intensity up.
Yet I'm lucky enough to still receive as much – if not more – love and attention from my spouse as the day we got together, and hope I reciprocate in kind. I'm almost sheepish to admit that we can't get to midday without one of us sending an "I miss you!" text to the other.
One reason I think we don't have that "itch", as it were, it because we've been open and honest for years about connections with other people and being monogamy-adjacent. It's not a taboo subject for us; we accept the realities of staying happy in a loving, long-term relationship.
Unfortunately, I'm now of the age where many of my peers who also got together with their spouses in their early/mid twenties are actually getting divorced. Of the friends of mine who have headed that way, they've come to unreconcilable differences because both partners have changed so much since they first met.
That's why I think the seven-year itch is the real deal. Over a period of that many years, everybody changes. If you're fortunate (as I have been) you'll change together, and continually re-negotiate your relationship as time goes by – continually ensuring you're both satisfied.
Others – for a bevy of reasons – can't do this. Or they fall into a rut. Or they realise the life they have isn't what they'd hoped for.
Is there any way you can beat the seven-year itch? A strategy to combat disenfranchised relationships and not feel so restless?
I honestly believe the only way around it is to never stop talking, and never stop touching. These are both things we humans need (and what Monroe was on about in her film).
Both are ways of communication that increase affection, ease tension, and are generally pretty fun. But don't wait until your seven-year anniversary is on the horizon to be conscious of this. If you can do it well before, you might avoid that itchy feeling altogether.