Ask away. I will be happy to field questions such as:
How many fireworks will you be setting off to celebrate this momentous event?
How much booze did you administer to yourself and/or your child(ren) to get through this process?
How many new swear words did your older children learn from you while this was going on?
I’m so happy it is finally over for you. Have a glass of Chardonnay for me and pat yourself on the back! With the diaper savings you should treat yourself to a day at the spa or a massage.
How can you be so sure that this is the last child for a woman as fertile as you are?
That’s an easy one. MrWhatsit exercised the surgical option. 
And, thanks, Perciful!
Congrats! Hope to be there soon myself.
Is it true that girls are easier to train than boys?
My sample size is extremely small on this one, but of my three kids, my daughter was potty-trained by age 2.5, whereas my boys were closer to age 3. I would not say that it was more “difficult” for the boys. They just weren’t ready as early.
Final? You’re never going to be a grandma?
Ha. Maybe, maybe not, but if I am, they better hire a nanny if they want help with potty training, because I ain’t doin’ it again. 
So, are you drunk yet? 
Congratulations!
Oh my god. The jealousy, it burns.
Really and truly or is this just day time trained? I want to be sure before I send over the dancing girls and the vat of wine.
Daytime only, but I am calling it anyway, mostly because changing the kid out of his nighttime diaper doesn’t bug me, whereas changing diapers all day long bugs me. A lot. Really, really bugs me. However, I will leave the dancing girls, wine, etc. to your discretion.
Congratulations!!!
I remember when I found out I was unexpectedly pregnant with my youngest. One of the first things I said (hysterically, through tears, and quite loudly - although he is my little snow pea now) was “but, but, but… I just got done with diapers!!”
QFT 
So - any bribery involved? Chocolate? Jelly Beans? New Tricycle?
So this was always really easy, the same thing worked every single time, and they were all potty trained by 18 months? Right?
(I love potty training advice…“all you need to do is…and that worked like a charm for me. I don’t understand why your three year old is still in diapers.”)
I remember once, getting in an elevator at work with one of my coworkers and her very young daughter and a bunch of strangers who worked in other offices in the building.
Coworker introduced me to her daughter. I said hello to her and she responded.
I can go potty all by myself!
Any stories like that?
Yes. See below.
I know, right? I especially love this when spoken in somewhat disapproving tones, like, “If you weren’t so lazy and indulgent, your kid would be out of diapers already. Like mine is. You should just do what I did. That would work. Lazy cow.”
Anyway, that said, the same basic technique actually did work on all three of mine, with some modifications. Basically around age 2-ish, I started introducing the concept of the potty and showing them what it was for and having them try to sit on it, etc. Then after weeks/months of having no success with this method, in frustration I would decide that this is it, we are going cold-turkey with no diapers. A special trip to the store to buy new cool character underpants, and then usually on a Monday morning for a week when we didn’t really have to go anywhere, we’d get started. The kid would be in either underpants only, or totally naked, and I’d keep a close eye and rush him (or her) off to the potty when it looked like something was imminent. Any success, no matter how small, was met with effusive praise and a chocolate chip. (Yes, I bribe.) Accidents were shrugged off with “Oh, an accident, that’s not good,” and quickly cleaning up. I did not make a big production out of accidents.
I’m not sure if the preceding weeks/months of “potty introduction” paved the way, or what. I kind of feel like the cold turkey method will work if your kid is ready, and won’t work if they’re not, and there aren’t that many reliable ways to tell if they’re ready. Whatsit the Youngest was going for long periods of time with a dry diaper, and that was about the only sign that he showed.
Anyway, that’s the method that wound up working for me. Other people have had success using different methods as well.
Zebra, I do not have any stories exactly like that, but I will tell you that once when Whatsit Jr. was about 4 years old, we had to leave the playground very quickly because he decided to whip it out and just start peeing right there in the sandbox. Not one of my finer parenting moments.
About the same age we were out at the Minnesota Arboretum. Way out from the buildings where there are bathrooms. And my son had to go. And we said “when you are out here like this, its ok to sneak back into the trees.” So he did. There really wasn’t another option - he wasn’t holding it for the twenty minute walk back.
And then showed off his “pee outside” skill at daycare the next week.