We went through a massive pile of stuff in the loft last year - my degree notes, DH's degree notes, letters from friends at university, job applications, cards from relatives who have since died...
We binned nearly all of it, but you know what, actually it was lovely to leaf through it with our teenagers/kids of early university age, and realise just how young we were (when we thought we were adults who knew it all).
DH said at one point, 'What did we keep all this stuff for?' The answer, I think, is that that week was exactly what we'd kept it for, and now it could all go.
You could do the same with your kids: keep bits for a year or even 10, look at it, laugh at it, exclaim at how little they were at the time, photograph it and then bin it.
They will very rarely remember the pictures that mysteriously go missing, but they may well enjoy the few bits that you keep.