You know how you can always remember exactly where you were when truly historic moments occur?
I, for example, can vividly recall walking along Hastings beach in Sussex when I was just 12 years old and seeing a newspaper headline saying ELVIS DEAD, shedding a tear in my old Daily Mirror office on learning that Princess Diana had died, and dining on a tiny 50ft sand-dune in the middle of the Indian ocean in the Maldives when Barack Obama was elected President.
Well, one thing's for sure, I'm also never going to forget what happened to me at 10.32pm last night.
Because that was the moment when Susan Boyle ran down a flight of stairs at the Fountain Studios in Wembley, North London, flung herself into my arms, and planted a five-second 'smacker' right bang on my lips!
It wasn't entirely unexpected.
A few minutes earlier, Susan had declared her feelings towards me in a rather more public way by dancing a little jig of joy on stage after winning last night's first Britain's Got Talent semi-final, and shouting: 'THIS IS FOR YOU, PIERSY BABY!'
But that was positively restrained compared to what happened backstage.
To say Susan was pleased at getting through to the final is probably the understatement of the century. You have to remember that until a month ago nobody had ever heard of her, but now she is the most downloaded, and talked about, woman on the planet. The pressure that comes with all that attention is absolutely huge, and I could tell she was incredibly nervous when I spotted her standing on her own in a corner backstage before the show started.
Then she came out and missed her very first note on Memory, and I think everyone watching feared it had finally got to her.
But Susan quickly recovered, got into her stride, and ended up delivering an absolutely stunning version of the Cats musical classic that brought house down, and thrilled the world all over again just as she did in her original audition.
If you thought she looked thrilled on stage, you should have seen her off it. She was absolutely exploding with excitement, relief and pure, unrestrained joy.
'You did it!' I said to her, as I spied her heading up the stairs near the judges' dressing room area.
'Oh Piersy!' she shouted, then skipped down the stairs, jumped on me and kissed me full on the lips for quite some time.
'I've been kissed now!' she laughed, then she danced another jig, and ran off again.
I'll be dining out on that for the rest of my life!
Susan's a fantastically unspoiled, delightfully warm lady, with a wicked sense of humour and a love of life that endears her to everyone. I couldn't be happier for her that she is now living her dream.
But anyone who thinks BGT is now a foregone conclusion is crazy. Diversity were absolutely brilliant last night, and their big dance rivals Flawless perform tonight. Either of those acts could definitely win the show. As could at least five or six others who you will see over the next few days.
The live shows couldn't have got off to a better start. Though I'd just like to say a special word about poor young Natalie, who was distraught at missing out on her final place. I was watching as she walked off the stage at the end crying, and thinking, like everyone, 'I hope her mum's here somewhere.' Well, she was, waiting at the bottom of the stage steps, to take her into her arms and console her. And by the time she studio lights went up after the show ended, Natalie was smiling.
But the big question now is this: Susan Boyle has laid down her marker, can anyone beat her?
Find out what's going on in Piers' world at his official website: www.officialpiersmorgan.com