The 'let them' theory changed 2 million people's lives. The 'who says' theory is the easy alternative.

Just when you thought you'd mastered the art of letting people do whatever the hell they want (thanks, Mel Robbins), along comes another theory to completely flip your mindset upside down. And honestly? I'm here for it.

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The 'Let Them' refresher (because we all need one).

The "Let Them" theory became everyone's favourite anxiety-busting mantra. Mel Robbins basically told us all to simply — let people behave as they wish, let situations unfold as they will, and conserve your energy for things within your control. 

The gist? Your sister wants to skip the family barbecue for her annoying friends? Let her. Your kid wants to quit the sport they've been doing for years? Let them. It's about accepting what you can't control and redirecting that energy into what you actually can.

Enter: the 'Who Says' theory.

But here's where things get interesting. Kate Halfpenny, a columnist for The Age, has introduced what might just be the perfect counterpoint to all this letting.

The "Who Says" theory was born from the most relatable conversation ever: a friend complaining about her bra cutting into her shoulders. Her other friend's response? "Who says you have to wear a bra?". And just like that, a theory was born.

While "Let Them" is about releasing control over others, "Who Says" is about releasing others' control over you. It's the difference between accepting someone else's choices and questioning why you're making choices that don't actually serve you.

The genius of 'Who Says'.

As Halfpenny puts it, "The beauty of 'Who Says?' is it exposes how many of our daily choices aren't really choices. They're habits we've inherited from a collective consciousness that nobody can actually identify".

It's about "trying to work out why you're following rules set by faceless, nameless authority figures". And honestly, when you put it like that, it sounds absolutely bonkers that we don't question these things more often.

Listen: Mia, Jessie and Holly question their 'who says' choices on Out Loud. Post continues below.

My personal 'Who Says' audit.

I personally wear a bra more from an occupational health and safety perspective. But, after decades of following invisible rulebooks, here's what I'm questioning:

Who says you have to wait for a man to propose? Hang on, who says we even have to get married? (And if you do, who says you have to change your surname?) Okay as a divorcee, I had already arrived on these 'who says' independently and anecdotally…

Who says you need to say 'bless you' after someone sneezes?

Who says kids need ironed school shirts?

Who says you need to own property in this lifetime?

Who says women can't have hairy chins? (Okay, I'm still working up the courage on this one.)

Who says we can't have icecream for dinner?

Who says you need to 'dress for your age?'

Who says kids' birthday parties require party bags?

The list could go on forever, and that's exactly the point.

The perfect partnership?

What it's got me pondering, is this: what if we didn't have to choose between these two theories and we blended them together? "Let Them" teaches you to let go of putting energy into controlling others, while "Who Says" teaches you to stop letting others control you. It's like having the perfect set of boundaries — internal and external.

"Let Them" might help you stop obsessing over your friend's questionable dating choices, but "Who Says" might help you realise you don't actually have to be in a relationship and be dating anyone just because society expects it.

The bottom line.

Both theories essentially boil down to the same thing: taking back your power. Whether that's the power you're wasting trying to control others, or the power you've unknowingly handed over to invisible social expectations.

So maybe 2025 isn't about choosing between "Let Them" and "Who Says" — maybe it's about using both. Let them live their lives, and you live yours. But make sure the life you're living is actually yours to begin with.

Now, if you'll excuse me, I have some serious rule-questioning to do. Starting with, can I really pull off a beard?

Who says I can't?

Feature Image: Instagram/@melrobbins / Supplied

You can find Kate Halfpenny's book 'Boogie Wonderland' here.