It is yet another example of Harry's complete failure to accept that his status has changed. Working royals try to avoid clashes , those on the periphery don't. Harry is the latter but thinks he is the former
Well put as ever, @MrsLeonFarrell, but I'm not sure if anyone's yet mentioned the criticism H&M have taken for constantly hijacking royal events with some silly stunt
Maybe the "Let's share the diaries" is an attempt to deflect this, as in "We could have avoided it if they'd only told us!!"
And yes, I realise that birthdays, Trooping the Colour, Remembrance Day and so many others fixed points which even Harry might be aware of, but since when did the facts interrupt his silly excuses and constant claims about everything all being someone else's fault
... like we needed him thrusting and highlighting his groin after his comments in spare!
Edited to add don't go there, @jeffgoldblum - please don't go there 
As mentioned before, between the frostbite, circumcision stories, accounts of losing his virginity and more Harry seems to have an almost infantile obsession with his groin area, and I'd have thought we'd already heard enough about it without thrusting fingers pointing it out