My sister got me a baby book for DS1. Despite not having had a a child yet, I kind of hinted to her that I'd probably be too busy actually BEING a parent than writing down my experiences of it, and she poo-poohed it. Needless to say, I filled in about 2 pages, in between DS's screaming bouts of colic, and never bothered with the rest. My MIL got me a baby memory box for DS2 and I'm afraid it went straight to the charity shop after he'd been born . (he was a nightmare baby)
While I LOVE being a mum I guess I'm just not sentimental about all that kind of stuff. I kept DS1's hospital ID bracelet until he was about 1 and then looked at it one day and noticed it had a distinct yellowish taint from a disastrous early nappy change, and promptly threw it in the bin. I HAVE got a lock of DS1's hair that got too long when he was 2, and it was just so cute that I wanted to keep it, but I must admit I do look at it from time to time and don't feel THAT nostalgic, and wonder why I kept it. I have also kept a tiny newborn hat that both DSs wore, but it was hand knitted by my mum and it took her AGES, and that's more the reason why I kept it.
I am not at all a cold-hearted type of person and am hugely sentimental, just not about STUFF, possessions, first this and that or whatever. My memories are what is important, but now I'm thinking that when I'm old and forgetful that maybe I'll regret not having kept/written down anything, I don't know.
Are you really kicking yourself? If I want nice memories of them as young babies, I just get a few old photos out, give the kids a hug and all the warm, nostalgic feelings come flooding back. Mind you, my 2 are boys, and I'm pretty sure that when they're older, they're not going to be in the least bit bothered by the fact that I never kept their first pair of bootees. Oh yes,and I kept both huge sets of "new baby" cards for a while, then thought "why" and went through them and just kept a couple for each.
As for red books, I wrote quite a lot of details in DS1's. Nothing in DS2's and he only saw the HV twice since birth too. Totally normal, from what I've heard!
Be careful though - I was a first child, and when I was about 8 noticed that there were LOADS of baby photographs of me, and only handful of little sis, and I took it upon myself to inform her that it must be because she was adopted. (she wasn't ) She was paranoid about that for years!!!! My DS2 has hardly any baby photographs cos I was too busy trying to stop him crying to get him to look at the camera. Plus, he wasn't the best looking baby in the world, bless.