It's easy to see in retrospect, with GE2020 vision.
There was a lot of talk of political plates shifting, a palpable sense of aspirational anger and a mood of revolt.
Coming closer to the election date, with polls showing Sinn Féin in the lead, there was an air of wild abandon in this country that I haven't seen since Italia '90. It translated into an electorate where one in four of those around you voted Sinn Féin.
Of course, even acknowledging this is enough to make certain types reach for the smelling salts. Some have lost the plot altogether and are having screaming tantrums over a democratic result.
They don't seem capable of accepting that fundamental principle of a republic: the people are entitled to their view.
Far be it for me to presume - but I'd say it's a fairly safe bet that these are the same people who were blithely unaffected by a Fine Gael leadership that sacrificed society for economy.
In all likelihood, they were cosy under a government for the wealthy by the wealthy - and, as Irish author Robert Tressell once put it, "selfishly interested in maintaining the present state of affairs".
Like many of Fine Gael's own star politicians: safely protected by class from ever finding themselves on the sharp end of the widening wealth-inequality divide.
Do they ever go past the top of their driveways, at all, I wonder? Turn off Dermot Bannon and switch on to stark reality?
Because out in the real world, what many voters were painfully aware of was a scale of social injustice in Ireland not seen for generations, and completely unacceptable in a supposedly modern country.
They saw a government that seemed to have a wilful inertia on issues that cut deep into the Irish psyche: poverty, housing, inequality. That disproportionately affected those we cherish: children, the sick, the old.
And they shouted stop. We want a fairer society.
Anyone who does not understand why the voters turned away en masse from the Fianna Fáil-Fine Gael duopoly and towards the party seen as the real opposition is - fortunately for them - out of touch with how chronic the situation has become for many.
This election was the masses against the classes. It was renters against rentiers. And it was bolstered by those compassionate comfortable who stood up on behalf of the uncomfortable.
Ordinary citizens were raging at Fine Gael driving the car into the ground on housing and health and seeming to justify 4,000 homeless children and kids eating their dinner off the streets as collateral damage.
We were becoming an anti-family country that de-prioritised children. It's absolutely abnormal to have an education system where up to one in four kids in disadvantaged schools is homeless.
Those on the margins - hard workers living in relative poverty due to paying half their income in rent - had understandable and real fears that they could be next. And all Leo and Fine Gael could do was bang on about our booming economy and further antagonise voters who had been left behind by it.
So why, exactly, did these voters turn to Sinn Fein?
Firstly - like it or loathe it - in a new decade, many people see the party as having evolved under Mary Lou McDonald and decided to give it a chance.
The scolding commentariat had plenty to do with its success. Sinn Féin was then positioned as anti-establishment, further energising its support base. Media and politicians focused on the terrible past that - sorrowfully, regretfully - we cannot do anything to change now; as well as on the future which, again, you cannot control, no matter how hard you try. What you don't do can have consequences too.
Those stuck in the social emergency of today do not have the relative luxury of such concerns. For them, it's about now.
Also, Fine Gael, in pursuit of the "liberal" vote, created a kind of zombie apocalypse of politicised voters, who then turned left when it came to a general election.
Fine Gael flirted with a kind of nationalism-lite during the Brexit negotiations, where it foolishly positioned itself as the good guy to stand up to those idiots in Britain.
So on social media, we saw the same bandwagoning for Sinn Féin as we did with Repeal and gay marriage.
Republicanism is in vogue again. This time - in response to social issues - it seems more in the Wolfe Tonian spirit of liberty, equality and fraternity.
I believe Charlie Flanagan's RIC/Black and Tans commemoration fiasco was the tipping point.
It reignited a spark of latent patriotism in many who felt that the social ills Fine Gael presided over were tantamount to treason in a country whose first principle is the welfare of the child.
The Eoin Ó Broin effect was significant: there was a cohort of voters caught in rental limbo who went for Sinn Féin just to put Ó Broin in as housing minister. Fianna Fáil should have backed his rent freeze instead of the landlords and it could be in a better position today.
But ultimately, the murmuration towards the biggest left-wing party came down to this question: who was most successful in demonstrating to the electorate that they cared about Ireland, and its people?
And the clear answer was: Sinn Féin.