I guess I look at it slightly differently. My mother wasn't perfect, she taught me an awful lot, loved me with all her heart, and we talked all the time. But no way could she teach me everything I might ever need to know. We led very different lives in different generations, and we really didn't need the same information.
I have been a good mother to my daughters and raised them well- but no way could I have had the time to impart every bit of my accumulated knowledge to them...there would have been no room for sometimes merely enjoying each others' company. Besides, I'm sure they would not have wanted me to prattling on and on to them with advice and 5 million factoids. I say just cover the necessary info (like sex and health and safety etc) as best you can and let them figure out some of the little details for themselves.