Thank you for your replies.
It would seem that my thoughts are following what you suggest.
Regarding the 'Magnum incident', I ate that more as a test, with the resultant check showing me how disapproving my wife can actually be with just a look.
If you follow a LCHF diet but suddenly fancy a pizza for example, the impact of that in the middle of a low carb desert would be what? Would it be classified as falling off the wagon, impinge on an individuals progress?
Off the wagon... Oh, I don't know. We all topple off at one point or another, often around the holidays and such. It's just a phrase to indicate a deviation from the diet, not the amount or duration. I guess that's for the individual to decide. As for having a one-off, it could kick you out of ketosis, should you follow a keto-diet, but it might not. We're all different, and some can just drift in and out of ketosis without problems. Others experience keto-flu all over again, and that's preferably avoided. (Fatigue, malaise, headaches...). Do keep in mind that carbs demand carbs... Once you've had a peak, your body'll ask for more, often that very day, if not a mere few hours later. Same as it would with drugs, really. It's easier to just keep going than to have one-offs that'll make you want more. To me, anyway. You might be different. And, there's fathead pizza, if you're up for cooking from scratch, which is low carb. I can't be bothered, so I'd just do an omelette with what I'd usually toss on a pizza on top. Cheese, deli meats, mushrooms... Also, if you've been at it with the low carbing for a while, a steep climb in blood sugars can make you feel very grotty until they come down. But that's, again, not the case for everyone.
When my mom got ill and passed away, I just quit caring about the whole diabetes thing all together. Mom first, and I'd get back on the wagon when the worst had passed. Going back and forth to Tilburg from Baarn almost daily while caring for her meant a lot of roadside foods, and grieving demanded cookies and chocolate, plain and simple. Not, excuse the pun, going to sugarcoat that. Since last week she's in an urn in our home, most of the paperwork is sorted save for the tax form (which I expect to get in another month or so), her flat's keys have been handed in, so everything's practically done and dusted... My husband is back to working regularly, -he was ill for a long time with long Covid- and my own days have gone back to the way they used to be before everything went to hell in a handbasket, for the most part. So. Back on the wagon I go. Circumstances are not quite ideal yet, but I have a rythm to my days now, and a little less stress to deal with, so I have no more excuses. It hasn't been easy so far, but after a while of eating like I shouldn't, I could expect keto flu. (Mind you, I have plenty of broth and such around to make up for the electrolytes I'm losing, so I got that sorted before starting!). But all in all... That's what I call having fallen thoroughly off the wagon. I may not have gone back to eating like I did before my diagnosis, but the cookies and chocolates were NOT blood sugar friendly. Far from it. They were nice, for a while... But I can do without. And without the gained weight!
Basically, we just give you some ideas on what could work for you. Don't get hung up on terminology, dogma's, what have you. Just figure out what works for
you. I get carb-creep if I do have a one-off, I will crave more, so I usually just steer clear, present circumstances excluded. Others can't stick with a diet unless they have a carby meal once a week or once a month. Find what works for you, what makes this sustainable for the long run. We know the basics, we know what affects what.... But only you know what works for you.