Let this be a thread where we admit our little blunders.
I'll start with this one that I keep doing: I've lived in the UK for seven years now. Also, I was a military brat growing up. You'd think the 24-hour clock would be old hat for me. But nooooooo. I mean, for the most part, it is... I can easily "translate" it in my head most of the time. However, many afternoons around 1:30pm, I think "oh, it's 3:30pm... I need to do the things soon." And at 2pm, I'm thinking, "ack! Nearly the end of the day!" But, in fact, I've still got two hours to go.
Whyyyyyy? Why do I still see 14:26 on the clock and panic because I haven't even started the washing up yet? I should know better by now.