Am evidently a freak.
I remember a fancy dress party when I was 6 - Alice in Wonderland theme, I went as the cook who shakes pepper on the baby when he sneezes.
I had a fab party dress with a sort of tabard that went over the top, black velvet dress with a high waist, and this ribbon embroidered top part in loads of colours it was THE fanciest thing I owned and I cried when I grew out of it!
I remember my 8th, swimming pool party, my sister pooed in her costume and a classmate had a massive paddy about not getting to go on the floats (because she couldn't get on them, not because she wasn't allowed). There was also drama because someone else who hadn't RSPV'd turned up with their younger sister!
I remember the butterfly cake, the maypole cake (big cake in the middle with a maypole, cupcakes all around it attached by ribbons, all nicely iced) the wild cat island cake from Swallows and Amazons, it had matchmakers chopped up for logs.. and the dinghys with the right flags on them.. all made by mother, sometimes with help from the teenager next door.
I remember the time my mother thought green food colouring in the cheese sandwich spread would be a whizzo idea and no one at it cos it was the colour of snot (she froze them. I had green cheese sandwiches for lunch for weeks after that).
I remember a lot, about most of them, mine, my sisters, friends - I am 42. I remember my 12th when my dad decided on his return from Aus (well from friends in Liverpool where he'd stayed the previous night after getting back) to come home for my party and got the car wedged in the multistorey carpark and rang Mother to rescue him and she left us, a bunch of 11/12 year olds with the 17 year old boy next door who was fiiiiiiiiiiiiiiiiiiiiiiiit... omg. I don't think he EVER recovered from the trauma!
These memories DO stay, the efforts ARE worth it, and you certainly never forget the parent who is evidently hating it and thinking its a waste of time!