IT began as a tentative and somewhat uncertain flash but by the end of the trip, it was a steady, warm and radiant beam.
If Queen Elizabeth had finally gotten to know "the neighbours" over the course of her four-day trip here, then so too had we come to see a completely different side to the stiff monarch we had viewed from afar.
There was nothing cold or regal about her manner, and this was no mere "cordial" visit. This was the British head of state, overwhelmingly determined to melt the last frozen depths of Anglo-Irish relations.
And with meaningful actions, heartfelt words and a genuine smile that spoke volumes, she did so.
In a remarkable turn of events that nobody could claim to have foreseen, a genuine tie of friendship between us and the queen appears to have sprung up.
And judging by the genuine frequency and breadth of her smile while she was here, this unexpected development has made her very happy.
Landing in Baldonnel on Tuesday, the queen had obviously been a little ill at ease, unsure of her welcome on Irish soil -- but determined to send a definite signal, touchingly eager to please in emerald green.
Her smile, though broad, was almost shy as she emerged from her chartered jet and met with Tanaiste Eamon Gilmore and his wife, Carol, at the windy military aerodrome.
Forging fast friendships with President Mary McAleese and her husband Martin on her first formal stop-off at Aras an Uachtarain, we saw an increasing warmth developing.
And when she humbly bowed her head in tribute to the fallen patriots at the Garden of Remembrance, the final bitter shards of suspicion and hurt fell from our hearts.
Though highly aware of the deep symbolism of Croke Park, she was visibly heartened by the down-to-earth welcome extended to her by GAA president Christy Cooney and her smile blossomed.
By the time she gave her extraordinary speech and used her "cupla focal" at the state dinner in Dublin Castle, the queen was amongst firm friends. In a sweetly refreshing remark to Mrs McAleese after an informal-style toast, she confessed: "I like this clinking glass."
We saw even more of this "smiling queen" as she flapped her arm at her husband in protest after he got a young jockey to gallop on a racing simulator at the National Stud.
Later she confessed to singer Mary Byrne that she was a fan of 'The X Factor' and traipsed happily around the Rock of Cashel.
Finally able to meet the Irish public on an unscheduled walk around the streets of Cork and the queen was in her element.
The British and international press have made much in the past about the queen's "rare" smile.
Tell that to the Irish.