I totally agree. Parenting is learned. You can read about it in a book, but you only get information. Actually doing it and gaining the experience (making some mistakes) is what makes you a better and more prepared parent.
Now nurturing I feel is different. Yes it is a quality of a good parent, but you dont read about it in a book and you certainly dont learn it overnight. I feel that to a certain extent nurturing is either in your programming or it isnt. Its a part of your personality. What makes you you. Society doesnt change it, knowledge wont change it, and you cant change it even if you tried. It is just one of those things that you do with instinct. Comforting a hurt child, reasuring them that the dark is nothing to be afraid of. Always showing sympathy to their needs.
Thats just what I think.