Blimey! @DottyHarmer addresses those who 'claim' that their lateness is an inherent trait - I assume she's talking about those of us with a medical diagnosis from a psychiatrist?
What does she need, to supervise the MRI for each of us in turn so she can issue approved friends with an 'oh yes Dotty sees that your brain is actually physically different now' sticker? I know I have ADD because I got to massive doses of methylphenidate and they made bugger all difference. Methylphenidate is a dopamine reuptake inhibitor. That proved my body just plain doesn't make any dopamine. I need to take a dopamine stimulant to achieve the metal state you have when you open your eyes in the morning. Have a look at what makes your NT body release dopamine to make you feel good about your achievements - now think about a lifetime of never getting any when you do those things. Feeling good from dopamine is what keeps NT people going back to positive patterns - being on time, remembering to put the bins out, taking the laundry out the machine and getting it dry and ironed, going to bed on time, eating lunch.
Without medication, I can regularly forget to eat, wee, exercise, look after myself, do regular little tasks - because there is no mental 'reward' released. So that fuzzy warm feeling you get when you arrive somewhere on time, have the kids bags all ready on a Sunday evening, get your ducks in a row...I just don't get that. Ever. Not mentally don't understand it, just physically never receive it. Having medication now actually helps me build towards wanting to repeat those activities and patterns, because after 4 decades of never getting them, I finally can.
Without medication, you telling me to sort my act out and always be on time is as much help as me shoving someone with anxiety into a lecture hall of 400 people and telling them 'don't worry, it's fine, all you have to do is talk.' Or telling someone with depression to 'cheer up'.
In fact, I absolutely do try to consider other people's anxieties with my scheduling and not put them in that position because of my timing...I'm late for stuff that benefits me far more often then I am to meet ups with them, I assure you. I don't do it on purpose.
I'm addressing this in detail because every time anyone says 'we'll make allowances for you', it seems the allowance is to say 'try this strategy that works for an NT person to be on time'. And also because lots of people seem to think there's a massive cohort of lazy/late on purpose people. I'm less convinced about that BECAUSE when you think about it, how many people do you know who really regularly struggle with it? Is it 30%, or is it more like 5-10%? Do they tell you that they TRY to get it right, but seem to always drop the ball, no matter what. If that's the case, the chance is FAR higher that they have ADD/ASD brain chemistry that doesn't process reward/timeline/scheduling in the same way as yours than that they are obnoxiously selfish. Of all the people I've ever met, I can think of one or two who were really uninvested in turning up on time. But many more who struggle with several of those aspects of organisation and timing that sit squarely with ADD (or dopamine deficiency syndrome, if it were renamed with a more accurate medical term). And try and try, but repeated fail with reliable timekeeping.
You got quite upset about me comparing my condition to someone born without a leg. Yet I was born unable to produce dopamine. A T1 diabetic cannot produce insulin. Why are their two conditions valid to you as a limitation that counts, but mine isn't just because you can't see it? It's not my inability to timekeep that has parallels with someone in a wheelchair, it's my inability to produce dopamine. That is a medical limitation. My limitation just results in you banging away incessantly issuing instructions to me to make my brain work like your brain. It won't (without medication at least).
I fully understand that my condition impacts all around me. I work very hard on minimising that. But my god, the mental pasting I've had for 40 years from people like you on the occasions I drop the ball - because as you've demonstrated here, people like you always assume that everyone is just like you, and people like me (diagnosed or not) couldn't POSSIBLY be wired any different - is every bit as unpleasant as everything you've written in this thread. It's also very apparent that regardless of the evidence presented, you feel that I should just be able to switch on 'caring' about things in the same way you do because they are important in society. I can't. There's no raw material to work with without the medication. That chemical 'leg' is missing. That's not an excuse. That's just a medical fact.
I have strategies. One of them is to be so busy, that every waking moment is crammed with stuff to do, so EVERYTHING is a short deadline, because that stimulates the adrenaline, endorphins and cortisol to act in place of dopamine instead. Rather than 'I'll do this because it's a good idea and I will feel content with my achievement' I get 'OMG if you don't leave now social services will take your children away/you'll lose your job/the electricity will be cut off/no one can eat this week/the client bid will be lost/your child will not be invited again'...and so on.
It's quite exhausting in comparison to dopamine-driven reward 'normal', and certainly the polar opposite of sitting around being 'ready' because that in itself makes you feel good! And it is also the reason behind others trying to explain to you that having buckets of spare time allowed does not actually improve the outcome. And why there is no ability to prioritise, because nothing generates 'reward', even when you get it right.
But when I read "Today I have to leave the house at 12. I have done nothing all morning except await my hour of departure. That is what a chronically punctual person does - be ready two hours early.", actually, I'm left wondering whether we've got it all wrong, and whether it is, in fact, me carrying you in society? Because sitting around for 2 hours doing nothing at all in order to be on time for the next thing is surely a massive underachievement in a day? If I did that, I could only get 4 things done. Perhaps your perspective is so skewed that you feel 4 things done well punctually is better than 18 things done and one of them 15 minutes late?
There we will, again, have to agree to disagree. But at least I hope I have explained why ADD bodies work the way they do (and some elements of ASD can be similar), and why applying your strategies doesn't help them unless the condition has actually been identified and medicated effectively.
I do look forward to receiving the invite to your MRI assessment so I can be awarded my 'oh yes, you do actually have a chemical shortfall' badge, I'll save the date!
and @Gothichouse40 if you want to understand why those with ADD (even if undiagnosed) have inconsistent abilities to turn up on time for different events, have a read of this - there's a good section on the measured improvement of time estimation for specific (monetary in this case) rewards:
www.ncbi.nlm.nih.gov/pmc/articles/PMC6556068/