How bizarre. As it happens, I have a birthday this year, so I’m something of an expert....
My Uncle has a favourite ‘joke’ that he tells every year, that never fails to greatly amuse just under two people. He will always say “I’ve just turned….!” And then swap the digits around e.g. ‘just turned 27’ when he’s now actually 72. Poor old chap will be 77 on his next birthday, so he won’t get his moment of ‘hilarity’ this year.
Please somebody find a link to that thread with the batty mum randomly adding years to her children’s ages! I agree that there’s a big difference between ‘just turned 2’ and ‘nearly 3’, but you don’t just round up without saying ‘and 8 months’ or ‘nearly’. It’s still very odd when adults do it, though. Dave Gorman mentioned it in one of his programmes, where people would describe themselves as ’27 and a half’ or whatever. I don’t know if they were trying to be wacky or if they genuinely thought people would expect different behaviour/knowledge/skills from a 27-and-a-half-yo than from a boring old 27yo.
Goodness! You feel you have a right to go around asking people their age or their children's but they don't have the right to say their age how they see fit. How entitled is that? Now, that's odd. Worse than OP.
In the right contexts, your age isn’t necessarily a deeply personal state secret that it’s offensive to ask others about in conversation. Nobody said that the other person reacted angrily or accusingly – most probably just perplexed at being told a pointless confusing lie. Regardless, you don’t have the common ‘right’ to make up your age ‘how you see fit’ – any more than you can just introduce yourself as Angela Hernandez tell people a random name that isn’t yours or one you’re known as, or claim to be a national of a country you have no connection with whatsoever.
Still a full on lie but adding-years-to-your-age lie, not shaving it off
To be fair, it’s not a ‘full on’ lie; not necessarily even a lie at all, depending on your perspective. The word nearly makes all the difference, as it makes it clear that you’re rounding your age (and under 10% isn’t always an outrageously large amount to round up or down) rather than stating an accurate fact.
As it happens, I needed to hire a van when I was 24 and about 8 or 9 months - many years ago - and I found quite a few companies that would gladly have let me hire any from a wide choice of lovely new-ish vehicles, had I been 25. Those few little months made all the difference, as I ended up with a thrashed, aged old heap that everybody stared at when you drove past (the engine sounded like you had it in 1st gear, even in top gear on the motorway) from the ropiest area of the city, where the van-hire place themselves warned me strictly not to park in the area outside of their compound). Not actually being 25, that was one of only two choices available to me – the other being to transport a Luton-load of bulky furniture on the bus or train.